" Hey, what's up?"

"Good morning. This is {Your Name} from {Company}. How may I assist you?"

"Can you talk now"?

close the conversation

encourage the speaker to share more

end the discussion politely 

The person is not near the phone.

The call cannot go through because the person is already on another call.

The phone call has been rejected. 

Disconnect the current line and start a new call

Ask the caller to call back later

Transfer the call to another person or department

to hate each other

to make sure you both understand each other.

to make sure you interrupt others quite well

To ask the caller to hang up

To request a call back late

To inform the caller that the line was busy