はず (should be, ought to be)

[a_korsakova]

Please help)) Can I use this はず with plain past form of a verb?

e.g. Kare wa mou kaette kita hazu desu.
or should it be: Kare wa mou kaette kuru hazu desu /or something else/????

Thanks

[zakojanai]

Well, the answer to your first question is yes. I think the first sentence is fine, but the second sentence might be ok too (though I'm not sure you can use "mou" in that context). It just depends on what you want to say. If you're trying to put something in the past tense, then yes, you change the verb before "hazu" to plain past form. But if you leave it in the dictionary form, it just makes it future tense.

I think this should clear up any misunderstandings: http://www.guidetojapanese.org/should.html

[a_korsakova]

勉強になりました、ありがとうございました。
just was a little bit confused with an explanation of this grammar point in one book/ thanks for a link - it's pretty useful.

Nastya