My book has one example of the use of the second one; こうこうのとき, いいがくせいでしたか which essentially is asking when you were in high school were you a good student though i am confused why こうこう instead of こうこうせい but that is a whole nother problem.

I doubt its as simple as one is a current tense and one is a past tense when. perhaps one is the question when and the other is a time when?

I have no idea what to tag this please fix for me.


You're on the right track. いつ is an interrogative, a question word. It's used to ask when something happened or will happen, not to talk about a particular time period. In English, we say:

When I was in high school.

In Japanese, it's:


(There's nothing wrong with saying こうこうせいのとき; it's just a little less common, probably because it's an extra word. In English, you can say, "Back in high school" or "When I was in high school" or "When I was a high school student...")

いつ and とき are never interchangeable. For example, you can say:


When is the class? If you replaced いつ with とき, the sentence would make no sense.


These have different meanings:

At this time, ...

とき means “time” and can be used to state a time period. This is translated to “when” in the sense of “at that time in which I was”


When I was in high school, .... (In high school...)

Using 高校生{こうこうせい} or 学生{がくせい} for “student” is also acceptable.


When I was a high school student, ...

This can be used with a noun:


When I was a child, ... (In my childhood...)

It can also be used with a verb or condition. In this case it’s usage is similar to ら for “if”:


When I am hungry, ...


If I am hungry, ...

So 時{とき} is used to state a time period in a subordinate clause, even if that time period is hypothetical or hasn’t occurred yet.


いつ is used to ask a time period that the asker doesn’t know yet. いつ is only used in questions. 「いつですか?」 means “when?” and is used in exactly the same way for times as 「何{なん}ですか?」 for “what?”.


When are you going to high school?

Note that いつ and とき have different usage and cannot be used interchangeably.

What time?

いつ for “when?” and 何{なん}時{じ} for “what time” (what hour) can also be confused:


What time is (your) lunchbreak?

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