English phonetics, phonology, and morphology are fundamental areas of linguistics crucial for understanding the structure and function of the English language. This guide provides a comprehensive overview, breaking down complex concepts into easily digestible sections, perfect for students preparing for exams or simply deepening their language comprehension. We'll explore everything from how sounds are made to how words are formed and meaning is conveyed through intonation.

Understanding English Phonetics: The Sounds of Speech

Phonetics is the study of speech sounds themselves – how they are produced, their physical properties, and how they are perceived. It's the physical and concrete aspect of speech.

The Articulators: How We Make Sounds

Sound production begins with airflow, which is then shaped by various parts of our vocal tract. These are called articulators.

Breathing System: The diaphragm, lungs, bronchi, bronchioles, and trachea work together to push air up, providing the necessary airflow.
Voice Box (Larynx): This cartilaginous structure houses the vocal cords. These muscles vibrate to create voiced sounds. The glottis is the space between the vocal cords, which can be open, narrow, or closed (e.g., for a glottal stop).
Cavities: These air spaces amplify and shape the sound. They include:
Pharynx: Connects the larynx to the mouth.
Nasal Cavity: Gives a nasal quality to sounds like /m/, /n/, /ŋ/.
Oral Cavity (Mouth): Contains the tongue (changes shape, blocks airflow), teeth (form sounds like /θ/, /f/), lips (shape or close for sounds), alveolar ridge (behind upper teeth, for /t/, /d/, /s/), hard palate (roof of mouth), soft palate/velum (opens/closes nasal passage), and lower jaw (adjusts mouth space).
Active vs. Passive Articulators: Active articulators move (tongue, lips, velum), while passive ones remain fixed (teeth, hard palate) but interact with active ones.
Cavities as Amplifiers: Pharynx, nasal, and oral cavities act like speakers, altering sound volume and quality, boosting or cutting frequencies, and contributing to a sound's unique timbre.

English Vowels: A Deeper Dive

Vowels are sounds produced without blocking the airflow through the mouth. They are typically voiced and shaped by the tongue's position (front/back, high/low) and lip rounding.

Cardinal Vowels: A set of reference vowels that describe the extreme positions of the tongue in the mouth, defining the vertical (close-open) and horizontal (front-back) axes of vowel articulation. In English, vowel quality (the sound itself) generally remains constant.
Short Vowels: English has several short vowels, such as /ɪ/ (bit), /e/ (bed), /æ/ (cat), /ʌ/ (cup), /ɒ/ (cot), /ʊ/ (book).
Long Vowels: English also features long vowels, denoted by /iː/ (seat), /ɜː/ (bird), /ɑː/ (car), /ɔː/ (law), /uː/ (goose).
Vowel Length Variation (Quantity): The length of a vowel changes based on the following consonant:
Very short: Short vowel + voiceless consonant (e.g., bit /bɪt/).
A bit longer: Short vowel + voiced consonant (e.g., bid /bɪd/).
Slightly shortened: Long vowel + voiceless consonant (e.g., beat /biːt/).
Longest: Long vowel + voiced consonant (e.g., bead /biːd/).
Vowel Classification Criteria: Vowels are classified by tongue position (front, central, back; close, mid, open), timbre (brighter for high vowels, duller for low vowels), and lip position (rounded, spread, neutral).
Comparison to Czech Vowels: English has significantly more vowel phonemes (around 20) than Czech (5). Czech speakers often struggle with differentiating English short vowels like /æ/, /e/, and /ʌ/ (e.g., bad/bed, cap/cup) and may not use the schwa /ə/ or lengthen vowels before voiced consonants correctly.

English Diphthongs and Triphthongs: Gliding Vowels

Diphthongs: Two Sounds in One

A diphthong is a single vowel sound created by gliding from one vowel position to another within one syllable. The first part is stronger and longer, while the second is weak, a soft glide. Examples include /eɪ/ (face), /aɪ/ (price), /ɔɪ/ (choice), /aʊ/ (mouth), /əʊ/ (goat), /ɪə/ (near), /eə/ (square), /ʊə/ (cure). Czech speakers often pronounce diphthongs as two distinct, strong vowels, which is incorrect in English.

Triphthongs: Three Vowel Positions

A triphthong glides through three vowel positions within one syllable. It's essentially a diphthong followed by a schwa /ə/. The structure is strong start → weak middle → very weak end. Common examples include /eɪə/ (layer), /aɪə/ (fire), /ɔɪə/ (lawyer), /əʊə/ (lower), /aʊə/ (power).

English Consonants: Shaping the Airflow

Consonants involve some degree of obstruction to the airflow. They are classified by their place and manner of articulation, and whether they are voiced or voiceless.

Voicing: Voiced sounds involve vocal cord vibration (e.g., /b/, /d/, /z/), while voiceless sounds do not (e.g., /p/, /t/, /s/).
Place of Articulation: Where in the mouth the sound is formed (e.g., bilabial /p, b/, labiodental /f, v/, dental /θ, ð/, alveolar /t, d, s, z, n, l/, postalveolar /ʃ, ʒ, tʃ, dʒ/, palatal /j/, velar /k, g, ŋ/, glottal /h/).
Manner of Articulation: How the airflow is obstructed:
Plosives (Stops): Complete blockage followed by a sudden release (e.g., /p, b, t, d, k, g/). Voiceless plosives /p, t, k/ are aspirated at the start of stressed syllables (e.g., pin [pʰɪn]), unless preceded by /s/ (e.g., spin [spɪn]). Final voiceless plosives are often unreleased in British English.
Fricatives: Narrowing of the vocal tract creating friction (e.g., /f, v, θ, ð, s, z, ʃ, ʒ, h/). These can be held continuously.
Affricates: A plosive followed immediately by a fricative, treated as a single sound (e.g., /tʃ/ as in cheap, /dʒ/ as in age).
Nasals: Air escapes through the nose (e.g., /m, n, ŋ/). The /ŋ/ sound (as in sing) never appears at the start of English words and is a single sound, not [ng]. Czech speakers often confuse /ŋ/ with /k/ or /g/ at word endings.
Laterals: Air escapes around the sides of the tongue (only /l/ in English). It has clear [l], dark [ɫ], voiceless [l̥], and syllabic [l̩] allophones. Certain 'L' sounds are silent before /d, f, v, k, m/ (e.g., would, calf, chalk, calm, salmon).
Approximants: Sounds made with less obstruction, resembling vowels (e.g., /r/, /j/, /w/). The English /r/ is post-alveolar and often retroflex. The /w/ sound is bilabial and rounded. Czech speakers often roll the /r/ in English, which is incorrect, and may replace /w/ with /v/ or vice-versa.

Consonant Clusters: Sounds Working Together

Consonant clusters occur when two or more consonants appear together in a word. Various phonetic processes affect their pronunciation:

Aspiration: A puff of air after voiceless plosives /p, t, k/ at the beginning of stressed syllables (e.g., pin [pʰin]). Not present after /s/ (e.g., spin).
Devoicing: A voiced sound becomes voiceless when next to a voiceless sound (e.g., have to /hæf tu/).
Assimilation: One sound changes to become more like a neighboring sound (e.g., good girl /gʊg gɜːl/ - regressive; in bed /ɪm bed/ - progressive).
Voicing Assimilation: A sound becomes voiced or voiceless based on its neighbor (e.g., with thanks → /wɪt θæŋks/).
Place Assimilation: A sound changes its place of articulation (e.g., that boy → /θæp bɔɪ/).
Coalescence: Two sounds blend into one new sound (e.g., /t/ + /j/ → /tʃ/ as in what you want → wotchu want).
Assibilation: A plosive turns into a fricative or affricate (usually before /j/, e.g., did you → /dɪdʒu/).
Elision: A sound is completely dropped, especially in fast speech (e.g., next day → /nɛks deɪ/, omitting /t/).

Exploring English Phonology: Sound Systems and Patterns

Phonology is the study of how speech sounds function in a particular language, focusing on abstract sound units and the rules governing their distribution and combination. It's the cognitive and functional aspect of sounds.

Fundamental Concepts in Phonology

Phonemes: The smallest distinctive unit of sound in a language that differentiates meaning (e.g., /p/ and /b/ in pin vs. bin). English has approximately 20 vowel phonemes (monophthongs and diphthongs) and 24 consonant phonemes.
Allophones: Contextual variants of a phoneme that do not change meaning. They are perceived as the same sound by native speakers (e.g., the aspirated [tʰ] in top and unaspirated [t] in stop are allophones of the phoneme /t/). They can be in complementary distribution or free variation.
Distinctive Features: Binary features (±) used to classify phonemes based on articulatory and acoustic properties (e.g., [+voice], [-nasal]).
Classification of Phonemes: Phonemes are classified based on the articulatory descriptions detailed in the phonetics section (place, manner, voicing for consonants; height, backness, rounding, tenseness for vowels).
Phonemic vs. Phonetic: Phonemic (/ /) represents the abstract, meaning-distinguishing level, while phonetic ([ ]) represents the concrete, physical realization of sounds.

Spelling-Pronunciation Correspondence and Irregularities

English has a deep orthography, meaning the relationship between written letters (graphemes) and spoken sounds (phonemes) is often inconsistent. This is due to historical sound changes (like the Great Vowel Shift), extensive borrowings from other languages, and the standardization of spelling that froze old forms.

Types of Correspondence:
One-to-one (regular): mat → /mæt/
One-to-many: a → /æ/ (cat), /eɪ/ (cake), /ɑː/ (father), /ə/ (about)
Many-to-one: /f/ → f (fun), ph (phone), gh (enough)
Silent Letters: Letters that are written but not pronounced (e.g., k in knight, p in psychology, b in debt).
Common silent letters include B (lamb), D (handsome), K (knee), G (gnaw), P (pneumonia), T (castle), W (who, write), L (calf, chalk, salmon).

Common English Words with Irregular Pronunciation for Students

Irregular pronunciation in English is widespread, especially in high-frequency words, personal names, and geographical names.

High-frequency Common Words: Often involve silent letters, unexpected stress, or non-standard grapheme-phoneme correspondences. Examples: said /sɛd/, women /ˈwɪmɪn/, colonel /ˈkɜːnəl/, yacht /jɒt/, island /ˈaɪlənd/, Wednesday /ˈwɛnzdeɪ/, answer /ˈɑːnsə/, debt /dɛt/, indict /ɪnˈdaɪt/.
Personal Names: Often retain historical or foreign pronunciations, making them highly unpredictable. Examples: Sean /ʃɔːn/, Siobhan /ʃəˈvɔːn/, Ralph /reɪf/ or /rælf/, Leicester /ˈlɛstər/, Beauchamp /ˈbiːtʃəm/, Mainwaring /ˈmænərɪŋ/.
Geographic Names: Frequently non-phonetic, reflecting archaic pronunciation, foreign etymology, or dialectal influence, especially in British and Irish place names. Examples: Worcester /ˈwʊstər/, Gloucester /ˈɡlɒstər/, Reading /ˈrɛdɪŋ/, Derby /ˈdɑːbi/, Greenwich /ˈɡrɛnɪtʃ/, Arkansas /ˈɑːrkənsɔː/, Houston /ˈhjuːstən/, Tucson /ˈtuːsɒn/.
Causes of Irregular Pronunciation:
Etymology and borrowing: Words preserve foreign pronunciations.
Sound change over time: Pronunciation shifted, but spelling did not.
Morphological preservation: Spelling maintains word roots across forms.
Standardisation of spelling: Printing press fixed spellings despite evolving pronunciation.
Dialect and regional variation: Place names reflect local pronunciations.

Rhythm, Stress, and Linking in English Speech

English is a stress-timed language, meaning stressed syllables are pronounced longer and clearer, while unstressed ones are quicker and often reduced. This creates a regular pattern of stressed syllables.

Rhythm: "I’ll MEET you at FIVE o’clock." (MEET, FIVE are stressed).
Stress Shift: To avoid consecutive stresses, stress can move (e.g., thirTEEN vs. ‘THIRteen PLACES).
Assimilation: A sound changes to be more like a neighboring sound (e.g., of course → /əf kɔːs/ due to voicing assimilation; that boy → /θæp bɔɪ/ due to place assimilation).
Coalescence: Two sounds blend into one (e.g., what you want → wotchu want where /t/ + /j/ → /tʃ/).
Elision: Sounds are dropped in rapid speech (e.g., next day → nex day, dropping /t/).
Linking: Words are pronounced in a continuous stream.
Linking sounds (vowels): A consonant at the end of a word links to a vowel at the start of the next (e.g., cold evening).
Linking R (British English): An unpronounced /r/ reappears if the next word starts with a vowel (e.g., four eggs → four-r-eggs).
Juncture: How listeners distinguish word boundaries in fast speech through intonation, timing, and aspiration (e.g., might rain vs. my train).

Intonation: The Music of English Speech

Intonation refers to the variation of pitch while speaking, superimposing meaning over words and sentences. It's crucial for expressing emotion, indicating sentence types, structuring discourse, and highlighting information.

Key: Speaker's neutral starting pitch.
Pitch Range: Difference between lowest and highest pitch.
Tonality (Chunking): Dividing speech into meaningful tone units (e.g., John arrived at seven this morning).
Tonicity: The syllable within a tone unit that carries the main pitch movement (the nucleus/tonic syllable), usually a lexical word. This focus can change meaning (e.g., John arrived at seven this morning vs. John arrived at seven this morning).
Tone: Identifiable pitch movements (fall ↓, rise ↑, level →, fall-rise ↘↗, rise-fall ↗↘).
Defaults: Fall for statements, wh-questions; Rise for yes/no questions, lists; Fall-rise for hesitation, reservation.
Focus of Information: The nucleus reflects the focus (broad vs. narrow). Contrastive focus highlights a specific item (e.g., I have spoken to him vs. Not to him, to her).
Functions of Intonation:
Attitudinal: Expresses emotion and attitude (e.g., Fall for finality, Rise for uncertainty).
Accentuating: Highlights prominent words (e.g., red dress vs. RED dress).
Grammatical: Reveals grammatical structure (e.g., Did you park the car? vs. Where did you park the car?).
Discourse: Focusses attention (given vs. new info) and regulates interaction (turn-taking).
Psychological: Segments speech for easier processing and memory.
Indexical: Reveals speaker's identity.

Syllable Structure and Vowel Reduction

A syllable is a basic unit of sound, typically containing a vowel sound (peak) and optionally consonants before (onset) or after (coda). English words can have one or multiple syllables.

Strong vs. Weak Syllables: Strong syllables are stressed (louder, longer, clearer), while weak syllables are unstressed (quieter, shorter, often with reduced vowels).
Vowel Reduction in Unstressed Syllables: Unstressed vowels often reduce to a weaker, simpler sound.
Schwa /ə/: The most common reduced vowel (e.g., about /əˈbaʊt/, sofa /ˈsəʊfə/). Many spellings can reduce to schwa (e.g., 'a' in attend, 'or' in forget, '-ate' in intimate).
Front Close Vowel /i/: Appears at the end of words ending in -y, -ey (e.g., happy, valley), in unstressed prefixes (e.g., react), certain suffixes, and unstressed grammatical words (e.g., he, the before a vowel).
Close Back Vowel /u/: Less common, found in words like you, to, do, who, and sometimes inside words before a vowel.

Weak Forms: Softening Function Words

A weak form is a shorter, softer pronunciation of a function word (preposition, pronoun, article, auxiliary) that occurs when it's unstressed in a sentence. This is key for natural-sounding English.

When to use strong forms: When the word is stressed, at the end of a sentence, for emphasis/contrast, or when used alone (e.g., Can you come? /kən ju kʌm/ vs. I can! /kæn/).
Common weak forms: include words like of /əv/, and /ənd/, the /ðə/, a /ə/, can /kən/, for /fə/, to /tə/, are /ə/, was /wəz/, have /həv/, etc.

Word Stress: Highlighting Importance

Word stress is the emphasis given to a syllable within a word. Stressed syllables are louder, longer, clearer (with full vowels), and higher in pitch.

Levels of Stress:
Lexical Stress (within words): Primary (strongest, e.g., reˈMARKable), Secondary (less strong, e.g., ˌundeˈSTAND), Tertiary (weak, but vowel not reduced), Unstressed (very weak, vowel reduced to schwa, e.g., aˈBOUT).
Sentence Stress (within phrases): Most important word(s) carry stress (e.g., At ‘five Paul ‘went ‘back ‘home a´gain).
Stress Placement Rules:
One-syllable words: Always stressed on the only syllable.
Two-Syllable Words: Nouns and adjectives usually stress the 1st (e.g., TAble, HAPpy). Verbs and prepositions usually stress the 2nd (e.g., reLAX, toDAY). If the first syllable is weak, stress often moves to the second (e.g., apPLY).
Three-Syllable Words: Rules depend on the last syllable's vowel length and word class.
Four or More Syllables: Often guided by suffixes.
Suffixes that attract stress: -ee (employEE), -eer (enginEER), -ese (JapanESE).
Suffixes that don't change stress: -ly, -ful, -ness (HOPEless).
Noun vs. Verb Stress: Stress can shift between noun (1st syllable) and verb (2nd syllable) forms (e.g., ˈREcord vs. reˈCORD).
Stress in Compound Words: Generally, stress is on the first word for noun+noun compounds (ˈbeauty contest), but there are exceptions (e.g., lemon ‘squash). Adjective + -ed compounds often stress the second element (bad-temˈpered).

Unpacking English Morphology: Word Structure and Formation

Morphology is the branch of linguistics that studies the structure of words and how they are formed. It examines the internal structure of words and the rules for combining morphemes, the smallest meaningful units of a language.

Introduction to Morphology

For example, in unhappiness, un- is a prefix, happy is the root, and -ness is a suffix. Each part contributes to the meaning.

Types of Morphology:
Inflectional Morphology: Deals with grammatical changes (tense, number, aspect, mood, gender) without changing the word's class or core meaning (e.g., walk → walked, cat → cats).
Derivational Morphology: Forms new words by adding prefixes or suffixes, often changing the word class or meaning (e.g., happy (adj.) → happiness (noun), teach (verb) → teacher (noun)).
Roles of Morphology: Helps understand word formation, indicates grammatical functions, and allows lexical expansion.
Grammatical Categories: These include number, person, tense, aspect, case, gender, mood, countability, and determination (articles).

Basic Morphological Units: Morphemes and Allomorphs

Morpheme: The smallest meaningful unit in a language. It can be a word itself or part of a word.
Free Morphemes: Can stand alone as a word (e.g., book, run, blue).
Bound Morphemes: Cannot stand alone; must be attached to another morpheme (e.g., im- in impossible, -ed in played, -s in dogs).
Derivational Morphemes: Create new words or change word class (e.g., un- in unhappy, -er in teacher).
Inflectional Morphemes: Add grammatical information without changing core meaning or word class (e.g., -s for plural, -ed for past tense, -’s for possession).
Allomorphs: Different forms (pronunciations/spellings) of the same morpheme that appear in different contexts but have the same function/meaning. For example, the plural morpheme -s has allomorphs /s/ (cats), /z/ (dogs), and /ɪz/ (buses).
Morpheme vs. Grapheme vs. Phoneme:
Morpheme: Smallest unit of meaning.
Grapheme: Smallest unit of writing (letter/letter group).
Phoneme: Smallest distinctive sound.

Types of Words and Word Formation

Word: The smallest independent unit of meaning that can stand alone. Made of one or more morphemes.
Monomorphemic Words: One morpheme (e.g., dog).
Polymorphemic Words: Multiple morphemes (e.g., unhappy).
Word Formation Processes:
Prefixation: Adding an affix before the base word (disobey, unhappy).
Suffixation: Adding an affix after the base word (kindness, teacher).
Conversion (Zero Derivation): Changing a word's part of speech without changing its form (e.g., the carpet (noun) → to carpet (verb)).
Compounding: Combining two or more base words (e.g., blackbird, toothbrush).
Inflection: Adding grammatical information without changing word class (e.g., -s for plural, -ed for past tense).
Clipping: Shortening a longer word (advertisement → ad, telephone → phone).
Borrowing: Taking words from other languages (pizza from Italian, ballet from French).
Back-formation: Creating a new word by removing an affix from an existing one (e.g., edit from editor, donate from donation).
Types of Word Relationships:
Synonyms: Similar meanings (happy/joyful).
Antonyms: Opposite meanings (hot/cold).
Homonyms: Sound/look same, different meanings (bank/bank).
Homophones: Sound same, different spellings/meanings (to/two/too).
Homographs: Look same, different meanings (lead (metal)/lead (to guide)).
Heteronyms: Spelled same, pronounced differently (tear (rip)/tear (from eye)).
Polysemes: Multiple related meanings (bank (money, river side)).
Capitonyms: Change meaning when capitalized (polish/Polish).
Word Classes (Parts of Speech): Nouns, verbs, adjectives, adverbs, pronouns, prepositions, conjunctions, interjections, determiners, articles.

Ambiguity in English: When Meaning Gets Tricky

Ambiguity occurs when a word, phrase, sentence, or expression has more than one possible interpretation. This can lead to confusion.

Lexical Ambiguity: A word has multiple meanings (e.g., bank).
Syntactic Ambiguity: Confusing sentence structure (e.g., "I saw the man with the telescope.").
Semantic Ambiguity: Words/phrases with multiple meanings or shades (e.g., bark).
Pragmatic Ambiguity: Depends on context, tone, or speaker's intention (e.g., "Can you pass the salt?").
Structural Ambiguity: Multiple interpretations due to sentence structure (e.g., "I saw the man on the hill with the telescope.").
Unambiguous: Clear, single meaning (e.g., "The sky is blue.").

A Look at Historical Linguistics and Typology

History of Linguistics: Understanding Language Evolution

Linguistics, as a formal discipline, emerged in the 19th and 20th centuries, though its roots are ancient.

Early Linguistic Traditions: From Pāṇini's Sanskrit grammar (Ancient India) to Greek/Roman focus on prescriptive rules and Medieval Latin studies.
Comparative and Historical Linguistics (19th Century): Focused on language relationships, reconstructing proto-languages, and identifying sound laws (e.g., Grimm's Law). Key figures: Franz Bopp, Jacob Grimm. This era emphasized diachronic linguistics (language change over time).
Structuralism (Early 20th Century): Founded by Ferdinand de Saussure. Key concepts include langue (language system) vs. parole (actual speech), synchrony (language at one time) vs. diachrony (historical change), and the idea of the linguistic sign (signifier + signified) as arbitrary. Language is seen as a closed, self-contained structure based on binary oppositions.
The Prague School (1920s-1930s): Key figures: Vilém Mathesius, Roman Jakobson. Main contributions:
Functional Structuralism: Language elements have specific functions within a structured system.
Distinctive Feature Theory: Sounds defined by bundles of features (e.g., [+voice], [-nasal]), laying groundwork for phonology.
Phonological Oppositions: Concepts like neutralization and markedness.
Functional Sentence Perspective (FSP): Focus on information structure (Theme vs. Rheme), influencing discourse linguistics.

Typology of Languages: Classification by Features

Language typology classifies languages based on common structural features, helping us understand their differences and relationships.

Genetic Classification: Groups languages by historical origin and common ancestors (e.g., Indo-European family, Germanic branch for English; Slavic branch for Czech). Language isolates have no known relatives (e.g., Basque, Korean).
Structural (Typological) Classification: Based on morphological and syntactic structures.
By Morphological Structure:
Isolating (Analytic): Single-word forms, minimal affixes, meaning from word order (e.g., Chinese).
Agglutinative: Many affixes, each with a clear grammatical function (e.g., Turkish, Finnish).
Fusional (Inflectional): Affixes express multiple meanings simultaneously (e.g., Latin, Spanish, Czech).
Polysynthetic: Many morphemes combine into very long words, expressing entire sentences (e.g., Inuktitut).

The Historical Journey of English

Understanding the history of English reveals why its phonology and morphology are the way they are.

Old English (c. 450–1150): Germanic origins (Angles, Saxons, Jutes), influenced by Latin and Old Norse. Highly inflected with flexible word order. OE cyning → ModE king.
Middle English (c. 1150–1500): Began with the Norman Conquest (1066), introducing Norman French. Loss of inflections, increased prepositions, heavy French vocabulary influence. ME quene → ModE queen.
Early Modern English (c. 1500–1700): Renaissance, printing press (William Caxton, 1476), and standardization. Marked by the Great Vowel Shift (long vowels changed pronunciation without spelling changes). Massive vocabulary expansion from Latin/Greek. Shakespeare played a key role. EModE name /neːm/ → ModE /neɪm/.
Modern English (1700–Present): British Empire, Industrial Revolution, globalization. Standardized through dictionaries (Samuel Johnson, 1755). Relatively fixed grammar, rich international vocabulary, simplified morphology. Ongoing influence from technology and global contact (e.g., email, selfie).

Regional Varieties of English

English is a global language with diverse regional varieties, differing in pronunciation, vocabulary, grammar, and spelling.

British vs. American English:
Pronunciation (Phonology): BrE is non-rhotic (/r/ only before vowels); AmE is rhotic. Vowel differences: BrE /ɑː/ vs. AmE /æ/ (bath), BrE /ɒ/ vs. AmE /ɑː/ (lot). AmE features T-flapping (/t/ between vowels becomes a soft 'd'). BrE often uses glottal stops for /t/ (bottle). BrE can have Yod coalescence (/tj/ → /tʃ/, Tuesday).
Spelling Differences: colour vs. color, centre vs. center, organise vs. organize.
Vocabulary: lorry (BrE) vs. truck (AmE), flat vs. apartment.
Grammar: BrE uses present perfect more (I've just eaten) vs. AmE simple past (I just ate); BrE can use plural for collective nouns (The team are winning) vs. AmE singular (The team is winning).
Other Varieties:
Scottish English: Rhotic, uses glottal stops. Lexicon: wee (small), bairn (child).
Irish English: Rhotic, dental stops for /θ/ and /ð/. Grammar:

English Phonetics, Phonology, and Morphology