Should; ought to

Uses

Present/Future

Past

1) advisability; desirability

I should study tonight. I ought to study tonight.

I should have studied last night. I ought to have studied last night.

2) 90% certainty

She should do well on the test. She ought to do well on the test. (future only)

She should have done well on the test. She ought to have done well on the test.

Uses

Present/Future

Past

1) polite question to make a suggestion

Shall I open the window?



2) future with «I» or «we» as subject

I shall arrive at nine. (will = more common)



Uses

Present/Future

Past

1) 100 % certainty

He will be here at nine.

He said he would be here at nine.

2) polite request

Will you please pass the salt?

Would you please pass

the salt?

Would you mind if I left early?



3) willingness

— The phone's ringing.

I'll get it.



4) preference

I would rather go to the park than stay home.

I would rather have gone to the park.

Examples

Functions

One should always be polite. How does one get to 5^th Avenue from here? One must keep one’s word.

one means any person, people in general. The subject of an impersonal sentence. (usually not translated)

This book is more interesting than the one we read last week. Here are two books. Which one would you like?

Any function for replacing a noun already mentioned.

One should take care of one’s health. One should take care of his health. One should take care of his or her health.

Notice the pronouns that may be used in the same sentence to refer back to one.

Examples

Functions

Both these children are mine.

These children are both mine.

Both my children are boys.

They both accepted the invitation.

You are both right.

They have both been invited.

We must both go there.

Both is plural in meaning and applied only to two persons or things.

a) Take either book. I don’t mind which.

The news didn’t shock either of them.

Have you seen either of your parents

today?

b) You may go by either road.

The houses on either side were tall and

big.

Either refers to two persons or things and has two meanings.

a) one or the other of two;

2. each of two; both.

Neither brother has been abroad.

We accepted neither offer.

Neither of the statements is true.

Neither means not the one nor the other.