How to sound more confident

There is something a lot of people do when they are nervous while speaking. This is true for both native and non-native English speakers.  It is actually a surefire way to tell if someone is not confident in themselves or what they are saying.  In fact, it is such a problem with native speakers as well that many business magazines such as Forbes, Fast Company, and Entrepreneur address this issue in their articles.  What is it?

It's the statement that sounds like a question: when your intonation rises at the end of a sentence that is not a question.

A couple of names for this are "upspeak" and "uptalk."  When we ask questions, the intonation at the end is supposed to rise.  When we make a statement, it is supposed to stay straight.  Here is a short video giving you a great example:

Maybe you do this because you are nervous.  Maybe you do this because a question tone sounds more inviting.  Perhaps you don't want to sound like you think you know it all.  Don't worry, just because you end a statement like a statement, you are not going to sound arrogant or cold.  It simply gives the listener the sense that you trust yourself, so they can trust you too.

Whether it is for the GBC test, a presentation you're giving, or during a conference call, making sure your tone at the end stays straight will go a long way toward sounding less nervous, and therefore, more confident.
—
surefire /SHUR-fahyər/ [adjective]—certain to succeed. // "While implementing methods that succeeded in their own countries may seem like a surefire plan, the reality is that if foreign companies ignore Japanese culture, they will end up failing miserably." 
address /ə-dres/ [verb]—to deal with or discuss. // "The Japanese government needs to address this issue swiftly."
go along way toward [set phrase]—to be very helpful in achieving something. // "The fate of the TPP will go a long way toward determining whether America is an Asia-Pacific power or not."