Usefull Phone Expressions

I rarely use the phone on the job. For me, e-mail is one of the most essential work tools. Perhaps it may be the main communication tool. However, when I’m on call, my phone is really important. I must be ready as soon as possible to get back to my boss' calls (or get back to another other person who has tried to reach me.)
Finally, if I can avoid it, I would rather people don’t leave messages because for me, is better to communicate directly.

Usefull Phone expressions

I rarely use the phone in on the job (or in work). For me, the e-mail is one of the most essential work tools. Perhaps it might be the main communication tool. However when I’m on call, in this case my phone is really important because I must be ready as soon as possible to get back to my boss if he calls or get back to another other person who has tried to reach me.
Finally If I can avoid it I would rather don’t leaving not leave messages because for me it is better to communicate with each other directly.

Good work!

Another way to say "I must be ready as soon as possible to get back to my boss" would be "I must be available to get back to my boss"