Have/has ставится, когда задается вопрос в Present Perfect Simple или в Present Perfect Progressive. Также, have или has может стоять в начале предложения, вопрошающего о наличии чего-либо. Пример: 1. Have you ever been in Moscow? 2. Have you got any sweets?
Различие в том, как будет задаваться вопрос: если has got, то Has he got a parrot?, а если же has, то Does he have a parrot? То же самое касается формы have.
1) I don’t know who else can do it.
2) I am not sure where else you can find it.
3) Tell me how else can I do this?
4) Say if anybody else can do this?
5) Ask why else they will do it.
1) Let’s go, or else we'll be late.
2) Let’s begin, or else we won't finish in time.
3) Tell me, or else I go away.
4) Do your homework now or else you'll be punished.