After I had been living in Denmark and speaking Danish on a daily basis for quite some time, I went back home to California only to have one of my best friends tell me that I "talk funny." I asked her what she meant and we figured out that I was speaking English (obviously), but using Danish intonation without realizing it! This made me sound "funny," or in other words, different than someone would normally sound who came from my home town.
Intonation refers to the ups and downs in the tone of our voices when we speak. Every language uses tone a little bit differently. Intonation is often times what holds us back from sounding like a native speaker in another language. If you can master a language's tone variations, you are well on your way to a more native-sounding mastery of that foreign tongue.
There are many ways to use intonation in English, but today I want to look at the two most basic: questioning intonation and statement intonation.
When you ask questions in English your tone usually rises over the course of the question. This signals to the listener that you are asking them something.
The tone of a statement is very different - it ends in a down tone. The tone signals that you are finished with that thought and moving on to something else.
As listeners, it has been found that we put more weight on a speaker's tone of voice than the actual words that are used. If you make a statement but end in an up tone, it will sound like you are unsure of what you are saying; you're using a questioning tone. This could be a real problem if you are presenting important information that you have researched or are trying to convince people to follow your lead. If you sound unsure, your listeners also won't trust what you're saying to be true.
Focus on the sound of your voice and how you use it when you speak. If you find that people don't take you seriously, your tone could be part of the problem.