Cambridge Grammar of English Hardback with cd-rom a comprehensive Guide

As long as, so long as 

As long as

and so long as occur frequently in informal spoken contexts. They may

both be used for real and unreal conditions:

As long as you promise to be back by 6, you can borrow the car.

As long as it doesn’t rain, we’ll have a great time.

I’m always fine 

as long as I can get about six or seven hours of sleep.

But I won’t mind too much 

so long as she’s coming back.

Suppose (that), supposing, assuming

Suppose (that)

, supposing and assuming can be used to imagine unreal

conditions:

A: You just have to say yes.

B: But suppose you’re not sure? Suppose you have to decide later? Suppose you

feel you have to go but don’t really want to?

Assuming we don’t sell the house, we can still move next spring. There are

always more buyers in the spring.