Dad said I can't go on the school trip to Russia __________ I buy some travel insurance.
unless
We need to take the first train in the morning. __________, we'll be late.
Otherwise
Mum says we can go if we promise to be back in time for dinner.
Mum says we can go, as long as / provided we promise to be back in time for dinner.
__________ Mum heard you say that! She'd be really angry!
Suppose
You can go there without a visa __________ you don't stay more than three months.
provided / as long as
If you didn't live here, where would you like to live?
Suppose you didn't live here, where would you like to live?
I have to go. If I don't, I'll miss the bus.
I have to go, otherwise I'll miss the bus.
The teacher said I wouldn't do well if I didn't do my homework.
The teacher said I wouldn't do well unless I did my homework. / The teacher said I would do well as long as / provided I did my homework.
OK, you can use my phone if you don't make long-distance calls.
OK, you can use my phone, as long as / provided you don't make long-distance calls.
You can borrow my book __________ you give it back to me tomorrow.
as long as / provided