Stressing a word when speaking, by saying it longer, louder or with higher intonation, will show the listener which word is key.
Intonation is sometimes described as the music of language. Without it, our voices are flat and lifeless, but with it, even simple language can be funny, memorable or moving.
Fillers are a great way to buy time when you speak, to sound natural and to hold the floor. What's more, they are essential to improving your fluency and delivery score on the G.B.C. test.