Sam doesn’t sleep/ isn’t sleeping now

Here’s how to choose between them:

• Sam doesn’t sleep (present simple)

  • Meaning: a general habit or truth about Sam. It’s about what Sam usually does, not right now.
  • Commonly used with qualifiers: Sam doesn’t sleep much. Sam doesn’t sleep at night.

• Sam isn’t sleeping now (present continuous)

  • Meaning: something happening right now or around the present moment. Sam is awake at the moment.
  • If you want to say the opposite (he is sleeping right now): Sam is sleeping now.

Quick examples you can use in exams:

• Habit: Sam doesn’t sleep much because he works late.
• Now: Sam isn’t sleeping now; he’s watching a movie.
• Current action opposite: If he were asleep right this moment, you’d say Sam is sleeping now.

If you tell me the exact context, I can suggest the most natural sentence.