Why doesn't my code work?

After seeing the solution I know this isn’t the most efficient way to do this, but why doesn’t this way work?

def check_for_name(sentence, name):
s = sentence.lower()
n = name.lower()
a = s.split(" ")
for b in a:
if b == n:
return True
return False

Well cannot tell for sure, though the clue is there. return False in a loop.