Okay, try going to a library and snatching a copy of a animation handbook. There are tons of different kinds, but almost all of them have at least two pages on lip syncing. You'll learn so much if you read or look through those sections.
But basically, all syllables don't end with the mouth closing. You and don't would be one full opening, going straight to belong, then the mouth closing for the second time, going to here, then the mouth closing. Try saying the phrase outloud in front of a mirror, and you'll see what I mean. By doing things like that before actually animating, by speaking in front of mirrors and taking notes of how many times the mouth closes and the basic shapes your mouth makes, animating lip syncs will be so much easier! Trust me, it will be. Plus, you don't have to take so many notes, especially when paired with the animation book.
I hope you excel at this! You already have tons of potential!