Correct intonation helps you sound natural in American English

. Intonation includes your tone, or the way you express a certain mood, feeling, or attitude through the sound of your voice. When someone is happy, you can understand their feelings without even understanding their words. We can usually detect anger, annoyance, sadness, frustration, surprise, and confusion just by listening to the rise and fall of someone’s voice.
Intonation in English helps you speak clearly and it helps you sound interesting! You’ll sound more fluent if you use correct intonation. If you get it wrong, it could be difficult to understand you, or worse, you might seem cold and rude. And I’m sure that you’re a nice, interesting person! We don’t want your intonation to send the wrong message.