Final answer:
The correct word to complete the sentence is 'than' because it is used for comparisons, while 'then' indicates a sequence of events.
Step-by-step explanation:
In the sentence "I would rather drive _____ walk", the correct word to fill in the blank is than. This is because than is used to compare two different actions or items, whereas then is used to indicate a sequence of events.
So, when choosing between driving and walking, you are comparing two possible modes of transport, and than is the appropriate choice. An example of a sentence using then correctly would be: "I went across the road and then bought a pair of shoes."
In this case, then indicates that one action (going across the road) is followed by another (buying a pair of shoes).