I've been waiting for a long time
Meaning: Say this for something that you have been doing for some time and still doing now or have just finished.
Example: I've been waiting for a long time. - Oh, I'm sorry, I'm late. He's been sleeping for 4 hours.
Example: I've been waiting for a long time. - Oh, I'm sorry, I'm late. He's been sleeping for 4 hours.
