I was wondering if there is a grammar rule about 2 actions happening at the same time.

Example:

I wrote in my diary while watching TV

or

I studied Japanese while listening to music

It certainly ain't in Genki 1 lol!

Cheers

I think one way to say this would be:

Terebi o mite iru toki ni (watashi no) nikki o kakimashita.

Terebi o mite iru = watching television
Terebi o mite iru toki ni = at/during the time of watching television, while watching television
(watashi no) nikki o kakimashita = (I) wrote in (my) diary

There may be other simpler ways of saying this, though. If it's not so important to say unambiguously that you wrote at the same time as watching TV, you could just say:

Terebi o mite, nikki o kakimashita.

But this leaves open the possibility that you first watched television, then wrote in the diary.

P.S.: I would have thought that it was "nikki ni kaku," but in sentence examples in the Tanaka corpus, both "nikki o kaku" and "nikki o yomu" occur several times.

cheers ^^ that's an interesting way of doing it.

Wouldn't ppl think that I only write in my diary when I watch TV though?

I just asked a 4th year from uni and he says...

nikki wo kiki nagara terebi miteta.

Learning sumthing new everyday

That must be "nikki o kaki nagara terebi miteta."

"kaki" is the noun form (-masu base) of "kaku", to write.

"miteta" is the plain continuous past of "miru", to watch; if you want to stick to the desu/masu level of politeness, say "miterimashita" instead.

This looks to me like it means "I was watching television while I wrote in my diary," which is a little different than what you asked about-- in your sentence, "I wrote in my diary while watching TV," the writing action is emphasized, so I think it should be the main verb of the Japanese sentence, with all due respect to the person you asked. So I think the sentence (in the desu/masu form) should be:

terebi mi nagara nikki o kaiterimashita.

(terebi mi nagara nikki o kaiteta).

But I hope a nihonjin will be kind enough to comment on this.

I don't think the sentence I suggested means what you are saying-- I saw plenty of similar sentences in the Tanaka corpus translated this way. But using "nagara" and the continuous past tense is probably more precise in meaning.

hehe sorry I typed in haste to go let someone in the door >_<

yeh the writing action was the more important action...
cos it is my Japanese journal which I'm going to try and write for the rest of the year.

Not that I think sensei will like the idea of me writing it whilst watching TV

I also wanted to write about surfing the internet.

Do you 'shimasu' the 'intaanetto'?

That's useful, I didn't know the polite for miteta.
I don't think we've done that form in class yet.
We've done miteita/miteimasu though.

*It's scary to think I'll be living in Japan for a year from next August*