Can I deduct business loss?

As a side business attempt, my son tried to sell tee shirts and hats.  He did it for a few months, along with his other 3 jobs, but it didn't work out.  Overall he lost about $1,000.00 on the venture.  Can he use TT Home and Business and use the Business section to show his business loss, den though he only did it for a few months and discontinued it all?  Thanks,