BRAIN GAMES III
Credit: GAMES Magazine - Oct. 1983
Will Shortz

1. What is unusual about the word LOITERING?
2. What verb is an anagram of its own past tense?
3. What common four-letter word has five anagrams?
4. What common verb has a past tense that is the past tense of another common verb spelled backward.?

Answers:
1. LOITERING is an anagram of LION (and) TIGER.
2. The past tense of EAT is ATE. 
3.  STOP, SPOT, TOPS, OPTS, POST, or POTS
4. The past tense of SEE is SAW, which is WAS spelled backward.