1. The king created a new tax to cover the cost of street lighting.

2. The king created a new tax so that he could cover the cost of street lighting.

3. The king created a new tax which covered the cost of street lighting.

4. The king created a new tax which could cover the cost of street lighting.

(Does #1 mean #2, #3 or #4?)

All four mean the same thing, but #1 and #3 are the best. The other two are wordy.

=)