should and if clause

[ridvann]

Hello,

I have been confused, and please help me about it.

Would you check these?

-If he should come, I will ask him about it.
He might come or not, mightn't he? Should implies less possibility. (it is used for future...It is ok)

But, my question is:

-If he should come, I would ask him.

He will not come, will he? Should shows less probability, doesn' it? But..It's unreal. It keeps me confused.Does it use for past or now and future?

Thanks....

[5jj]

In predictive conditional sentences, should can be used in the IF-clause, with a meaning similar to ‘happen to/chance to’ suggestingthat the speaker sees the possibility as real, but more remote than with an unmarked [present] tense:

- If he should come, I will ask him about it.
(- If he comes, I will ask him about it).


This is one of the few anomalies in the system. Should is the form of the modal shall that is distanced in reality or likelihood. Such distancing forms of the other modals are, logically enough, not used in a Predictive Conditional sentence implying a real possibility. This use of should is a one-off oddity.

In hypothetical conditional sentences, should can also be used in the IF-clause; it still has a meaning similar to ‘happened to/chanced to’ suggestingthat the speaker sees the possibility as more remote than a with a distancing [past] tense,

- If he should come, I would ask him about it.
(- If he came, I would ask him about it.)

The distancing verb form in the main clause (here: would ask) makes it clear that this is a hypothetical conditional, less likely, in the speaker’s mind, than the situation expressed as a predictive conditional.