Grammar | Modals / Should and Ought to

In the negative, shouldn't is more frequent than oughtn't.

 Should & Ought to

Definition:

Should and ought to have two possible forms:

1) Should / Ought to go : Present or Future situation.
2) Should / Ought to have gone : Past situation.

Meanings: Should and Ought to can export :

1) Advise.

2) Probably.

1/ Advice:

a) Present or Future situation: You should/ Ought to go = It would be wise of you to go.


1) The doctor tells me I should/ ought to stop smoking.
= ( It would be wise of me to stop smoking, but I still smoke.).


2) It's a pity smoking is allowed in Morocco cinemas.
= Smoking........ in Morocco cinemas. ( But it is .).


3) The young should/ ought to respect old age. ( But they don't ).


4) We should/ ought to ring him up now,..........we?


Remarks:
1) In the negative, shouldn't is more frequent than oughtn't.


2) In Reported speech introduced by Past verb, should and ought to don't change.
" You should/ ought to sell your car soon" he told me = he told me ( that)..............my car soon"

b) Past situation:

Yours should / ought to + have + Past participate.
You should / ought to have gone = It would have been wise of you to go.


The meaning  in past with these two forms is either Regret or Reproach about a Past action which
 - Didn't take place ( statement )
 - Took place ( Negatives )


1) We shouldn't / oughtn't to have invited her. = ( Regret : it would have been wise of us to invite her, buy we didn't).


2) He should / ought to have eaten so much. Now, he is sick.
( Regret: it would have been wise of him not to have been eaten so much, but he did).


3) You should / ought to have come yesterday. ( Reproach: but you didn't).


4) You shouldn't / oughtn't to have watched TV. ( Reproach: but you did )

c) Revision in contrast:

Missed exercises:
1) She should / ought to ............... ( Work ) hard in order to pass her exam this year
- She should / ought to.................( Work ) hard in order to pass her exam last year.


2) He should / Ought to ..................( Be ) more careful. The vase is broken now
- He should / ought to .............. ( Be ) more careful next time.


3) You shouldn't / ought to ........... ( Give ) the baby a knife, he may cut himself.
- You shouldn't / oughtn't to .......... ( Give ) the baby a knife, he has cut himself.

2/ Probability:

Should and ought to can also express Probability. The mean: It is.
Probable / likely that ..... The y could be replaced by Must or Will, buy Should / Ought to are less Certain that Must or Will.

a) Present or Future:

1) I don't know the answer myself, but ask your science teacher. He should / ought to know. = ( he probably knows ).

2) That should / ought to be Janet coming upstairs now. = ( That's probably Janet).

3) I've bought 30 sandwiches for the party. That should / ought to be enough. = ( That's probably enough )

b) Past :

It's 8:00. He left at 6:00, and the trip takes 2 hours. He should / ought to have arrived by now. = ( He has probably arrived by now ).