Present subjunctive (see Overview) is common in formal British English. In less formal English, we use a Present tense form (but not if the rest of the sentence is in the past), and we can also use should. (The examples below give alternative forms.)

We use Present subjunctive:

• in that-clauses after report verbs, adjectives or nouns to express plans, urgency, intentions or suggestions:

The police insisted the car (should) be moved immediately.
The police insist the car is / be moved immediately.

Words often followed by a Present subjunctive are:

Verbs:	insist, suggest, request, order, recommend, propose, think
Adjectives:	advisable, essential, desirable, preferable
Nouns:	decision, insistence, demand, requirement, condition

 

• after if: If he (should) be found / is found guilty, he'll be jailed for ten years.

• after whether: Whether she (should) agree / agrees or not, we're going to have to go ahead.

• after whatever: Whatever his reasons be / are, they are insufficient to excuse him.
  

• The Present subjunctive is common in particular phrases:

Far be it from me... So be it. Be that as it may... Suffice it to say... Come what may...
Heaven forbid! Long live the Queen.

We use Unreal Past (including Past Perfect) to discuss imaginary situations, to express impossible wishes, and to make proposals and polite requests. We can also use Past subjunctive:

• after if when we think it is unlikely or impossible that the condition will be fulfilled:

If she were to eat / ate fish more often, she might get to like it.

• to replace an if-clause when we imagine past, present or future events being different:

Had he agreed, he'd have become the team captain.
Were he to agree, he'd probably become the next coach.

• after if only to express regrets and frustration:

If only he were / was more adventurous.
If only I hadn't drunk so much coffee! (= but I did)

• after wish when we are wishing for the virtually impossible. For more reasonable wishes, we commonly use would or could:

I wish I weren't / wasn't having the injection tomorrow. (= but I am)
I wish I'd listened to you. (= but I didn't)
I wish you wouldn't shout all the time.

• after would rather and would sooner to express preferences:

Do you mean you'd sooner I weren't / wasn't here?
I'd rather you hadn't spoken so rudely to him.

• After as if and as though we use Present and Present Perfect forms to suggest something is likely to be true. Past forms suggest it is unlikely or untrue:
  
  The man speaks as if he has / had never heard of the place.
  He acts as though he owns / owned the place.
  
• after imperative suppose and imagine (Present tense is also possible):

Imagine he were to tell you / told you / tells you his most personal secrets.
Suppose she were to have followed / had followed your advice. (= but she didn't)

• after it's time ...:

It's time I wasn't here. (Past subjunctive is not possible)
It's time we left. / It's time to leave.