Student or Learner
Is "fight with someone" common? As I know, you normally say "fight or fight against someone". If you say "fight with someone", that someone is not your enemy, but an ally. Isn't it?
ex)Selkirk was born in Scotland in 1676. At age 19, he left home to become a sailor. One day while sailing, Selkirk fought with the captain...
'Fight with' can have two completely different meanings.
'I used to fight with my brother over who got the top bunk bed.' This means the speaker was physically fighting his brother in order to determine who would sleep in which bed.
'In the war, American soldiers fought with British soldiers in countless battles.' This means that the soldiers from both nations fought side by side against the same enemy.
So you have to use contextual clues in order to determine which meaning is correct in a given sentence or paragraph.