I've heard different things - on the one hand saying things like 高いか, きれいか, or
飲むか is too aggressive, but in my grammar book it says that か is used with
informal forms. Furthermore I'm told that instead of using か with informal
forms, one should simply slightly raise one's voice.

Finally, I've heard questions simply asked by using だ, such as in それがどういう意味だ?
or 何だ?

I'd appreciate some clarification. Thanks
CC BY-SA 3.0
2017-12-21T22:59:25.427
55331
2018-07-24T22:00:29.493
2017-12-22T05:15:30.407
9831
19109
question
particle-か
In informal speech is か used or omitted?
> 高いか, きれいか, or 飲むか

If you say them with slightly raising voice, they are questions, too
aggressive (or they sound rude, rough or impolite) and informal.  
Usually we say like 高い, きれい, or 飲む with lightly raising voice in daily
conversation instead.

By the way 飲むか with strong and without raising voice, it means "I reject to
drink". If you say "a verb + か" with this kind of voice it means to reject to
do the action of the verb.

> それがどういう意味だ? or 何だ?

If you say them with strong voice, they sound extremely aggressive, and in
general you can expect that a phrase inducing fights or quarrels like "文句あるのか？
_Are you complaining?_ _Have you any objection?_ or _Do you have anything to
complain about?_ " will continue.
CC BY-SA 3.0
2017-12-22T05:11:56.397
55339
2017-12-22T05:11:56.397
20624
55331
answer