@Mahmoud: No problem!
@Coffee: You are right. One could say 'have a nap.' However, the use of 'have' in that situation is not as common. The only time one might say 'have' instead 'take' would be someone trying to suggest a nap to someone without trying to sound too demanding. In general, you should use 'take.' I hope this helped. I'm sorry if this wasn't clear...
An opinion from a Canadian:
take a nap means start and complete a nap (a future plan)
- I need to take a nap very soon.
get a nap means have a nap and benefit from the result after the nap is completed (final result).
- I'll feel better after I get a nap.
Have a nap means "take and get' or 'start, complete and benefit from a nap'.
- I need to have a nap and I'll feel better after I have a nap
Confused now? :) ... I hope not...
In the UK 'have a nap' would be the preferred option. Just like 'have a shower' is preferred over 'take a shower.' Both verbs are however correct, there is a difference in regional preference.