"For how long" vs"how long"

[Banglardon]

What is the difference between For how long and how long? Are they both correct in the following sentences?

1- For How long are you here?

2- How long are you here?

3- For how long have you been here?

4- How long have you been here

 

[Yankee]

What is the difference between For how long and how long? Are they both correct in the following sentences?

1- For How long are you here? OR, What is the duration of your visit?

2- How long are you here? Same as above or "How long have you been waiting?" Depends on context.

3- For how long have you been here? "How long have you been waiting?" (or, in this area) Depends on context.

4- How long have you been here? Same as 3.

Y.

 

[emsr2d2]

We wouldn't use "How long are you here?" to mean "How long have you been waiting?" in BrE.

"How long are you here?" would be a shortened (and fairly unlikely) version of "How long are you here for?", meaning "What is the duration of your visit?"

 

[Tarheel]

What is the difference between For how long and how long? Are they both correct in the following sentences?

1- For How long are you here?

2- How long are you here?

3- For how long have you been here?

4- How long have you been here?

Only the fourth one is natural to me.