Given a disfluent sentence, modify the sentence to it to its equivalent fluent form, preserving the meaning of the sentence.

Example input: Who did the Han Chinese want to help the Khitan no I mean the Mongols fight?
Example output: Who did the Han Chinese want to help the Mongols fight?
Example explanation: The input initially means Khitan and then changes to Mongols, hence this is correct.
Q: When did the Germanic tribes claim territory in north and west Europe no wait tell me by when did the Germanic tribes not conquer the Celtic peoples?
A:
By when did the Germanic tribes not conquer the Celtic peoples?