combine into 1 question

[cuppycake..]

Hello

.my question is talking about if I can call it
question inside question or combine questions for example:
(Do you know if Mars has an atmosphere?? )
so when do we need this kind of questions ?why did not we use the qusetion directly?
(DOES mars have an atmosphere??)
and when should we use if ???
i'm sorry if these questions are a lot but I want to learn that

[5jj]

Hello

.mMy question is talking about if I can call it
"question inside question" or "combine questions", for example:
(Do you know if Mars has an atmosphere?? )
sSo when do we need this kind of questions ?w Why did not we use the qusetion directly

We can ask a direct question, "Does Mars have an atmosphere?", or phrase it as an indirect question:

Do you know if Mars has an atmosphere?
Can you tell me if Mars has an atmosphere?
I'd'like to know if Mars has an atmosphere.
Please tell me if Mars has an atmosphere.

Please remember to begin the first word of a sentence with a capital letter.

[cuppycake..]

I appreciate what you did to help me
Thank you very much. ^_^