Student or Learner
1.I don't love her because she is smart.
2. I don't love her, because she is smart.
The only differece between the two sentences is the comma between her and because in #2.
Is it true that this commma makes a big difference in meaning?
I heard that #1 means "I love her, but the reasin is not that she is smart", whereas #2 means "I don't love her. The reason is that she is smart".
#1 can have the meaning you say, but this is usually made clear by giving the real reason:
I don't love her because she's smart, but because she's rich.
Many people would prefer to re-phrase this to avoid any ambuguity: I love her because she's rich, not because she's smart.
#2 does indeed give the reason for your not loving her.