No French is the second...I guess
EDIT> I just googled...i was wrong...check the top 10
1. Mandarin - Number of speakers: 1 billion+
2. English - Number of speakers: 508 million
3. Hindi - Number of speakers: 497 million
4. Spanish - Number of speakers: 392 million
5. Russian - Number of speakers: 277 million
6. Arabic - Number of speakers: 246 million
7. Bengali - Number of speakers: 211 million
8. Portuguese - Number of speakers: 191 million
9. Malay ? Indonesian Number of speakers: 159 million
10. French - Number of speakers: 129 million
Arabic is No. 6...French is the last