How to express vague amounts of time?


I'm having trouble figuring out how to express vague amounts of time in
Japanese, such as `some number of months` or `some number of hours`.

I want to use this in a context where the specific number is neither important
nor known, but the factor of time passing/occurring is important. For example:

> `Some hours` later, he finished the test.
>
> Traveling to and staying in another country requires `some number of months`
> free.




Two constructions spring to mind here.

数{すう} can be used in place of a specific number, followed by a counter, to
mean "some" / "a few" / "several" (it doesn't really make a distinction in
this respect...).

> 数時間後、彼は試験を終わった。

This can be used in ways you might not expect:

> 数十秒 some tens of seconds  
>  十数秒 ten-(and-some)-odd seconds (between 10 and 19)  
>  二十数年 twenty-(and-some)-odd years

Alternatively, you can use 何 + counter + か.

> 他の国に滞在するなら、[何ヶ月]{なんかげつ}かは開いておかなければなりません。

The same kind of uses seen above for 数 also apply to 何.




Two constructions spring to mind here.

数{すう} can be used in place of a specific number, followed by a counter, to
mean "some" / "a few" / "several" (it doesn't really make a distinction in
this respect...).

> 数時間後、彼は試験を終わった。

This can be used in ways you might not expect:

> 数十秒 some tens of seconds  
>  十数秒 ten-(and-some)-odd seconds (between 10 and 19)  
>  二十数年 twenty-(and-some)-odd years

Alternatively, you can use 何 + counter + か.

> 他の国に滞在するなら、[何ヶ月]{なんかげつ}かは開いておかなければなりません。

The same kind of uses seen above for 数 also apply to 何.

