1)The weather may be warm enough for us to go swimming tomorrow.
We'll
2) Charles will teach us how to skateboard this weekend if it doesn't rain.
Unless
3) You don't want to watch TV? You can watch a DVD then.
Why don't you
4) Why don't you come along? Then we can hire two boats.
We can
1) We'll go swimming tomorrow, if the weather will be warm enough.
2) Unless it's rain, Charles will teach us how to skateboard this weekend.
3) Why don't you watch TV? You can watch a DVD then.
4) We can hire two boats if you come along.