If you have to talk on the phone in English, don't be afraid! The fear of talking on the phone in a second language will disappear if you practice often. The most difficult part about using the phone in a language that is not your own is the fact that you cannot see the other person's eyes, mouth, and body language. Although you might not be aware of it, in face-to-face conversation you lip-read and watch for smiles, frowns, and moving hands, all of which can help in understanding meaning.
In addition, it is true that telephone interaction is perhaps not taught enough in ESL classrooms, nor is textbook treatment of telephone conversation adequate. These deficiencies pose a serious problem for ESL learners, given how much everyone relies on the telephone in everyday life. Telephone talk appears to be one area in which ESL learners are particularly sensitive, since they frequently state that it is difficult to talk on the telephone and they either avoid or limit such interactions.
Speak Slowly and Clearly
Make Sure you Understand the Other Speaker
Use Businesses and Recordings
Learn Telephone Etiquette (manners)
Practice Dates and Numbers