You should write him a letter (否定句)
You _shouldn't___ write a letter _to__ him
He asked when we should leave (简单句)
He asked us when _to__ __leave_
There are a lot of things you could do(同意句)
You _have__ _got__ a lot of things __to_ ___do_
You should write him a letter (否定句)
You _shouldn't___ write a letter _to__ him
He asked when we should leave (简单句)
He asked us when _to__ __leave_
There are a lot of things you could do(同意句)
You _have__ _got__ a lot of things __to_ ___do_