We usually say:
How far is London?
But suppose if I am along the way to London, and very tired. Can I say:
How more far is London?
I am not a native speaker.
English Language Learners Stack Exchange is a question and answer site for speakers of other languages learning English. It only takes a minute to sign up.Sign up to join this community
The expression you are looking for is "how much further".
How much further is London?
"More far" is not a phrase you will generally find in Standard English; the word further expresses the idea.