I would like to ask you:
1) Is it OK to use "KEEP" in the PRESENT PERFECT
I have kept knocking on the door for 3 minutes now.
2) Is it OK to use "KEEP" in the PRESENT SIMPLE in this context
Two friends are at the office. One of them starts calling his wife on the phone every other minute. His wife hangs up on him but he goes on calling. After 10 minutes have passed the other guy asks the one calling.
Why do you keep calling her?
Would it be OK to use KEEP with the PRESENT SIMPLE, taking into consideration the fact that, the calling had been happening for 10 minutes only at the time of asking but apparently it had a potential to go on for some time.