Summary of Mastering English: Grammar and Vocabulary
Mastering English: Grammar, Vocab, & Communication Skills
Introduction
Animals play important roles in ecosystems and in people's lives. This unit focuses on how we speak and write about animals in English, using modal verbs (must, should, can, may, might, could, ought to, have to, will) and active/passive voice. You'll learn how to give advice, express obligation, possibility, permission, and how to change sentences between active and passive.
Definition: A modal verb is a helping verb that expresses necessity, possibility, permission, or ability (for example: must, should, can).
Definition: Passive voice is a grammatical construction where the subject receives the action (for example: "The dog was vaccinated"), while active voice shows the subject performing the action (for example: "The vet vaccinated the dog").
1. Modal verbs — quick guide
Key meanings of common modals
- Must / have to — strong obligation or necessity
- Should / ought to — advice or recommendation
- Can / could — ability (can), polite possibility or past ability (could)
- May / might — permission (may) or possibility (might)
- Will — future actions or willingness
- Might / could — weaker possibility
Definition: Obligation expresses something you need to do; advice suggests what is a good idea.
Forming sentences with modals (structure)
- Modal + base verb: should feed, must protect, can adopt
- Negative: modal + not + base verb: should not (shouldn't) harm
- Question: modal + subject + base verb: Can you help?
Practical examples:
- Owners have to feed their pets properly. (obligation)
- People ought to respect wild animals. (advice)
- Volunteers could rescue abandoned dogs. (possibility/suggestion)
2. Active and passive voice — patterns and practice
When to use passive
- When the doer is unknown: "Injured birds must be protected."
- When the doer is less important: "The shelter will save many puppies." (active) vs "Many puppies will be saved by the shelter." (passive emphasizes the puppies)
- To be formal or objective in reports and descriptions
How to form passive (simple tenses)
- Present simple passive: am/is/are + past participle — "Pets are vaccinated regularly."
- Past simple passive: was/were + past participle — "The kitten was examined by the veterinarian."
- Modal passive: modal + be + past participle — "Endangered animals should be protected."
Definition: Past participle is the verb form used in perfect tenses and passive voice (e.g., protected, rescued, examined).
Conversion practice (examples)
Active -> Passive:
- Families can adopt homeless cats. -> Homeless cats can be adopted by families.
- The government must punish animal abusers. -> Animal abusers must be punished by the government.
Passive -> Active:
- Animals should be treated with kindness. -> People should treat animals with kindness.
- The kitten will be examined by the veterinarian. -> The veterinarian will examine the kitten.
Table: Modal + Active vs Modal + Passive
| Modal | Active example | Passive example |
|---|---|---|
| should | People should protect wildlife. | Wildlife should be protected. |
| must | The government must enforce laws. | Laws must be enforced by the government. |
| can | Families can adopt cats. | Cats can be adopted by families. |
| may | Volunteers may rescue animals. | Animals may be rescued by volunteers. |
3. Useful practice exercises (self-study)
-
Change the following active sentences into passive (use correct modal forms):
- People should protect endangered animals.
- Volunteers could rescue abandoned dogs.
- Owners have to feed their pets properly.
-
Change the following passive sentences into active:
- Homeless pets can be adop
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Animals - Modals & Voice
Klíčové pojmy: Modal verbs express obligation, advice, permission, or possibility, Use modal + base verb: should feed, must protect, can adopt, Form passive with be + past participle: are rescued, was examined, Change active to passive by making object the subject and adding be + past participle, Use modal + be + past participle for modal passive, Use active when the doer matters; use passive when it doesn't or is unknown, Choose must/have to for obligations, should/ought to for advice, may/might for possibility, Practice aloud to hear active vs passive differences, In reports, passive emphasizes results rather than the actor, Match comparative clauses logically (The more... the more/less...)