One of the biggest problems is speed. Native speakers, especially business people, tend to speak very quickly on the telephone. Here are some practical tips to get native speakers of English to slow down!
* Immediately ask the person to speak slowly.
* When taking note of a name or important information, repeat each piece of information as the person speaks.
This is an especially effective tool. By repeating each important piece of information or each number or letter as the spell or give you a telephone number you automatically slow the speaker down.
* Do not say you have understood if you have not. Ask the person to repeat until you have understood.
Remember that the other person needs to make himself/herself understood and it is in his/her interest to make sure that you have understood. If you ask a person to explain more than twice they will usually slow down.
* If the person does not slow down begin speaking your own language!
A sentence or two of another language spoken quickly will remind the person that they are fortunate because THEY do not need to speak a different language to communicate. Used carefully, this exercise in humbling the other speaker can be very effective. Just be sure to use it with colleagues and not with a boss :-)!