English Grammar Reference: Verb Tenses, Conditionals and Modals

Passive Voice Conjugations

• Present: buy / are bought / are being bought
• Past: were bought / were being bought
• Future: will be bought / are going to be bought
• Perfect: have been bought / had been bought / will have been bought
• Modals: can be bought / could be bought / should be bought / should have been bought

Conditional Sentences

• First: If + present simple + future simple (will)
• Second: If + past simple + conditional simple (would)
• Third: If + past perfect + conditional perfect (would have + participle)

Reported Speech

Verb Shifts: buy → bought, are studying → were studying, called → had called, have seen → had seen, will → would, can → could, may → might, must → had to.

Time and Place Expressions

now → then, today → that day, here → there, this → that, tomorrow → the next day, yesterday → the day before, ago → before, tonight → that night.

Gerunds

Use gerunds after these verbs: admit, anticipate, appreciate, avoid, complete, consider, delay, deny, discuss, dislike, hate, enjoy, excuse, finish, imagine, keep, mention, mind, miss, postpone, practise, quit, recall, recollect, recommend, report, resist, resume, risk, stop, suggest, tolerate, understand, continue, begin.

Infinitives

Use infinitives after these verbs: agree, aim, appear, arrange, ask, attempt, be able, beg, care, claim, consent, decide, demand, deserve, expect, fail, hesitate, hope, learn, manage, mean, need, offer, plan, prefer, prepare, pretend, promise, refuse, seem, struggle, swear, try, use, wait, want, wish, like, allow, cause, challenge, forbid, force, hire, instruct, invite, order, permit, require, teach, tell, start, recycle, happen, come, undertake.

Connectors and Linking Words

• Contrast: however, whereas, although, in spite of, despite
• Addition: moreover, besides
• Condition: provided that, unless, as long as
• Comparison: the more I read

Obligation and Speculation

• Obligation: must (debes), have to (tenéis que), should (deberías), don't have to (no hace falta), needn't (necesario), mustn't (debes quejarte), not allowed to (no se nos permite).
• Speculation: must (debe ser), be sure, probably, may (puede), might (podría), maybe (quizá), can't (seguro que no).