I was reading this in a Japanese forum, and I don't quite understand the very end:

会話表現なら、アニメ見まくるだけで良いと思う。大事な表現は頻繁に登場するし、どんな場面でどんな表現が好まれるかもわかる。

He is replying to someone who is asking about how to increase vocabulary. I understand that he is saying that to increase your spoken vocab, watch lots of anime (he is talking about watching it in English). Then he says, important phrases will frequently show up, no matter what setting and no matter what kind of phrases are liked (by you? the person he is talking to?).... I don't understand the かもわかる part at the end.

Ah, if only I could read this to you, I bet you would understand right away..

「どんな場面でどんな表現が好まれるか」もわかる

In this case, も means "also" or "too".
The か is part of この(好)まれる, but I'm not sure hot to explain it...
it means something similar to だろう, but it's a form used when quoting something...

これは暑いものかわからない。(I'm not sure if this is something that is hot)
明日が雨なのか晴れなのか知るわけがない。(There's no way I'd know if tomorrow is rain or shine.)

ocircle Wrote:Ah, if only I could read this to you, I bet you would understand right away..

「どんな場面でどんな表現が好まれるか」もわかる

In this case, も means "also" or "too".
The か is part of この(好)まれる, but I'm not sure hot to explain it...
it means something similar to だろう, but it's a form used when quoting something...

これは暑いものかわからない。(I'm not sure if this is something that is hot)
明日が雨なのか晴れなのか知るわけがない。(There's no way I'd know if tomorrow is rain or shine.)

Questions that are quoted indirectly are usually followed by か; I don't think it's like だろう because you can have だろうか, it just indicates a question

Mind linking me to this forum?

Oh, you're reading the thread where I talked a little about AJATT?

The sentence you posted here means:

IMO you can learn everyday language just by watching tons of dubbed anime. Important phrases do appear in anime as frequently as they should, and you can also learn when to use which expression.

So, you got tripped up by どんな場面でどんな表現が好まれるかもわかる。? Its literal translation would be something like:

(You) will understand what kind of expression tends to be used in what kind of situation as well.

も here means "too," "also," or the like. Actually you can leave out も if you don't want to emphasize the sense of "also," i.e., どんな場面でどんな表現が好まれるかわかる。is also grammatical.

か here is to connect a question-ish clause to a verb. In this case, どんな... (what kind of...) is connected to わかる (understand). Question-ish clauses include "if" kind of sentence if the "if" means "whether." The examples ocircle gave are connecting "if" clauses to verbs, but the "if"s are actually "whether," hence the か.

If you want ab in-a-nutshell explanation, as yudantaiteki said, "Questions that are quoted indirectly are usually followed by か."

Ryuujin27 Wrote:Mind linking me to this forum?

I think it's this forums:
http://llt-anime.net63.net/index.php

The thread the OP is talking about is:
http://llt-anime.net63.net/viewtopic.php?f=18&t=74

EDIT: OOOOOOOOOOOOOOHHHHHHHHHHHHHHHHHHHHHHHHH, just saw your reply magamo, now I understand. Thank you! It turned out I was tripped up by the どんな, which I guess I have mostly seen as どんな＿＿＿＿でも form, so I was thinking more along the lines of "no matter what kind of scene, no matter what kind of expressions are liked" which was completely wrong, and thus I had no chance of understanding why かもわかる was there. I think if it had been read aloud to me (like ocircle was saying), the pauses in the sentence might have clued me in a little more as to how to split up the sentence. Anywho, thank you for your help, my Japanese is a little bit better now.