Key Idea: These patterns change the meaning of a verb: how real something is, how sure or necessary it is, who does it, who said it, and what form comes next.
| Type | Pattern | Example |
|---|---|---|
| Zero: always true | if + present, present | If you heat ice, it melts. |
| First: real future | if + present, will + base | If it rains, we'll stay in. |
| Second: unreal present | if + past, would + base | If I had time, I'd learn the piano. |
| Third: unreal past | if + past perfect, would have + participle | If I'd known, I would have helped. |
Modal verbs
- Ability: can/could. Permission: can/may. Possibility: may/might/could.
- Obligation: must/have to. Advice: should/ought to.
- Bare infinitive, no -s, no do: "she can", "should rest", "Can you…?"
- mustn't = forbidden. don't have to = not necessary.
The passive voice
- Move the object — The object of the active sentence becomes the subject.
- Change be — be + past participle: is cleaned, was built, has been cleaned, will be cleaned.
- Add by… only if needed — Leave out the doer when it is unknown or unimportant.
Good for formal reports, notices and processes. Mix it with active sentences.
Reported speech
- Statements: said (that)… Change the pronoun, step the tense back (is → was, will → would, can → could), and change time words (today → that day).
- Questions: asked if/whether…, with statement word order. "Where do you live?" → He asked where I lived.
- Commands: told/asked someone (not) to + verb. "Wait!" → She told me to wait.
Gerunds & infinitives
- -ing after enjoy, avoid, finish, suggest, keep, mind, practise, and after any preposition.
- to + verb after want, decide, hope, plan, promise, agree, learn.
- stop, remember, forget, try change meaning: "stop smoking" (quit) vs "stop to rest" (pause).
In an if-sentence, will and would never go in the if-part.
"If I ___ (be) you, I'd apply." were: the second conditional uses were for every subject.
"You ___ smoke here. It's forbidden." mustn't or don't have to? mustn't.
Make it passive: "Someone built the bridge in 1890." The bridge was built in 1890.
Report it: "I am tired," he said. He said he was tired.
"I'm thinking about ___ (move)." moving: a preposition takes -ing.