it's/that's

[thangtamfive]

Hello,

I would like to know for sure what is the difference between using it's and that's in sentences like "Is that such a problem to...?" Sorry if the question sounds too stupid, but I don't have this 'feeling' of the right variant yet. And I understand that, despite similar meanings, sometimes it does matter.

I think the answer must have been described in popular references, so if anyone points me to one of them, it will probably be enough.

Thanks.

[vijayjohn]

I guess I would say that in general, that makes it sound like you're referring to something very specific whereas it can often just be a dummy pronoun (a pronoun that's in the sentence just so that the sentence has a subject). I would say "is it such a problem to...?" instead of using that because it is just a dummy pronoun in this context. If you wanted to say "is it such a problem to make a Baked Alaska?" you could also say "is making a Baked Alaska such a problem?" and it would mean the exact same thing. It's just that you couldn't say *is such a problem...?