hardly

  1. I hardly ever take a bus.
  2. I hardly take a bus.
  3. He hardly ever goes fishing.
  4. He hardly goes fishing.
  5. I hardly (ever) think about him these days.
  6. I hardly think about him these days.
    Please check those sentences.
    If you find wrong, please correct and explain the reasons.

#2 seems strange to me. In this case “hardly” means “to a small degree/extent”, and you can’t really “take a bus” to a small degree/extent. #4 seems slightly unusual, though not actually wrong. The others all seem OK.