[Grammar] "All" takes SINGULAR and PLURAL

What is the difference between

"All is well" and "All are well."

Is the usage of "all" in the sentence below correct?

[h=3]It all just sounds like, oooooh.[/h]

mamen said:

What is the difference between

"All is well" and "All are well."

Is the usage of "all" in the sentence below correct?

It all just sounds like, oooooh.

Click to expand...

For your first question, the verb depends on what "all" refers to.

How is everything? All is well.
How are the troops? All are well.

I have no idea what your last sentence means.

mamen said:

Is the usage of "all" in the sentence below correct?

It all just sounds like, oooooh.

Click to expand...

It depends what all refers to. If it all = everything, then it's OK. As a written sentence, it doesn't work well because it is not obvious whether oooooh is meant to be positive, negative, a shock, etc.