English Grammar Essentials

The simple past tense of 'to go' is 'went' (for all subjects: I went, you went, he/she/it went, we went, they went). The past participle is 'gone'.

Form: have/has + been + verb-ing. Example: 'She has been studying for three hours.' It emphasizes the duration of an action that started in the past and continues.

Use 'a' before consonant sounds and 'an' before vowel sounds. Example: 'a book' (consonant sound), 'an apple' (vowel sound). Note: 'an hour' (silent h) but 'a university' (yu-sound).

The zero conditional expresses general truths or facts where the result always happens. Form: If + simple present, simple present. Example: 'If you heat water to 100°C, it boils.'

Third conditional: If + past perfect, would have + past participle. It describes hypothetical past situations and their imagined results. Example: 'If I had studied, I would have passed.'

'Could' expresses past ability ('I could swim when I was five'), possibility ('It could rain'), polite requests ('Could you help?'), or permission (informal past).

Passive structure: object + be + past participle (+ by agent). Example: Active 'The cat chased the mouse' becomes 'The mouse was chased by the cat.' The object becomes the subject.

Backshifting means moving the verb one tense back when reporting. Present becomes past ('I am happy' → 'He said he was happy'), past becomes past perfect ('I saw her' → 'He said he had seen her').

A defining relative clause gives essential information to identify the noun. No commas are used. Example: 'The student who won the prize is here.' 'Who' refers only to that specific student.

'Put off' means to postpone or to discourage/disgust someone. Example: 'We put off the meeting until Monday' (postpone). Example: 'The smell put me off my food' (discourage).

The error is subject-verb agreement. 'He' requires 'doesn't,' not 'don't.' Correct: 'He doesn't know the answer.' 'Don't' is used with I, you, we, they.

Form: Will + subject + be + verb-ing? Example: 'Will you be working at 9 PM tomorrow?' Used for actions in progress at a specific future time.