Why should this English "If" be translated? Is it a clause? If she spent five years in Paris,how come she can't speak a w

if translated as: if ..., if ...

This is an adverbial clause, which is an assumption contrary to the facts.

If she spent five years in Paris,how come she can't speak a word of French?

if she spent five years in Paris, how come she doesn't speak a word of French?