I read that need is seldom used in affirmative sentences. Is that so? Are the following sentences natural? Could you please correct me if they have a meaning different from what I have written in brackets?
1)You need to study hard if you don't want to lag behind. (strong advice? )
2) I need to go. I have a lot of things to do. (necessity based on circumstances?)
If I were a native speaker of English, I would never shut up. :-)