I have made up two similar sentences below.
(1) Tom will come here for three days next week.
(2) Tom will come here three days next week.
Some of my non-native English speaking friends and I think "for three days" means three consecutive days. The second sentence without "for" means three days that are not consecutive. But, my other friends think (2) is grammatically wrong when it is missing "for".
Please help me. Thank you very much for your help.