May / might

We can use 'may' to ask for permission. However this is rather formal and not used very often in modern spoken English

May I go to the concert? (This means the same as "Am I allowed to go to the concert?") As a result, using may could create some ambiguity. For example: I may go to the concert. This is ambiguous. Does it mean "I am allowed to go to the concert" or does it mean "I might go to the concert"? When you have a situation like this, use might (or a version of allow) to eliminate the ambiguity. For example: I might go to the concert. I am allowed to go to the concert.

might

We use 'might' to suggest a small possibility of something. Often we read that 'might' suggests a smaller possibility that 'may', there is in fact little difference and 'might is more usual than 'may' in spoken English.

She might be at home by now but it's not sure at all. It might rain this afternoon. I might not have time to go to the shops for you. I might not go.

For the past, we use 'might have :

He might have tried to call while I was out. I might have dropped it in the street.

Past Perfect simple OR past perfect continous

 

A.    The Past Perfect Simple

Forms:         After I had told him the truth, I felt much better.

                   When I arrived, they had already gone.

                   She said she hadn't met him before.

USES:

In reported speech: referring to things that had happened before the time of speaking/thinking.                    Sara told me she had met Dave the day before.                    I thought I had seen that man somewhere before.          The policeman man asked Mathew if he had witnessed the accident

In if-sentences, type III (impossible).                    The dog wouldn't have snapped at you if you hadn't teased it.                    If I had known myself, I would have told you.

B.    Past Perfect Continuous

Forms:         He was tired because he had been working hard all day.

She had been wandering around for some time before she asked someone the way.

USES :

For longer actions that had begun before a given time in the past and that were still going on at this given time.                    [The past perfect continuous relates to the past just as the present perfect continuous relates to the present.]                    When I got there they had already been waiting for two hours.                    [they had begun waiting two hours before and they were still waiting when I got there]                    The body had been lying unnoticed for a long time before it was found.

THE PRESENT CONTINUOUS TENSE

The present continuous  tense is formed with the present tense of the auxiliary verb TO BE + the present participle (the infinitive without to + ING)

Ex. I am working           We are not reading               Are you writing?

The present continuous is used

§  For an action happening now.

Ex.      It’s raining (now)   What are you doing?

 

§  For a definite arrangement in the near future (and it is the most usual way of expressing one’s immediate plans).

Ex. I’m meeting Peter tonight. Are you doing anything tomorrow afternoon?

Note that the time of the action is always mentioned, as otherwise there might be confusion between present and future meanings. GO and COME, however, can be used without a time expression.

VERB PATTERNS, CLAUSES OF PURPOSE, GERUND, PARTICIPLE

Verbs + -ing adore can't stand don't mind enjoy finish look forward to	doing swimming cooking		Notes We often use the verb go + -ing for sports and activities: I go swimming every day. I go shopping on weekends.
Verbs + to + infinitive agree choose dare decide expect forget help hope learn manage need offer promise refuse seem want would hate would like would love would prefer	to do to come to cook		Notes Help and dare can be used without to: We helped clean up the kitchen. We didn't dare disagree with him. We use have to for obligation: I have to wear a uniform. Used to (or would) expresses past habits: I used to smoke, but I quit last year.
Verbs + sb + to + infinitive advise allow ask beg encourage expect help invite need order remind tell want warn would like	me him them someone	to do to go to come	Notes Help can be used without to: I helped him do the dishes.
Verbs + sb + infinitive (not to) help let make	her us	Do	Notes To is used with make  in the passive: We were made to work hard. Let cannot be used in the passive. Allowed to is used instead: She was allowed to leave.
Verbs + -ing or to + infinitive (with little or no change in meaning) begin continue hate like love prefer start intend	doing to do
Verbs + -ing or to + infinitive (with a change in meaning) remember stop try regret forget	doing to do		Notes I remember posting the letter. (= I have a memory of the past action.) I remembered to post the letter. (= I didn't forget to do it.) I stopped drinking coffee. (= I gave up the habit.) I stopped to drink a coffee. (= I stopped in order to have a cup of coffee.) I tried to sleep. (but it was difficult) I tried counting sheep. (a way of getting to sleep.)