[Superman]

Express extreme frustration and anxiety. In fact, call him a nasty name for taking so long.

Or better yet, just give him the exact phone call tbat VaSteve suggested. Communicate. If you are concerned about his time frames, then ask him about those time frames, tell him you don't want to be a pest, but you are (would be) an excellent renter and would like to make this house your home. In sales, it's called "closing the deal." Not in a pushy way of course. Just sayin'.... "I want this job." or "I want to live in this house." And perhaps ask about timelines if that's important to you.