I'm a little confused about the Viet sentence structure... I'm brand new to the Vietnamese language and I'm still unsure about a lot of things that are probably considered basic to most of you.

Anyways, I was wondering if these phrases are written correctly, and if they aren't, if you could provide the correct phrase. I would be much obliged.

Tôi không hiểu tiếng việt - I don't understand Vietnamese

Tôi không có thể nghe - I can't hear

Tôi muốn ân bánh mì - I want to eat bread

Is this the correct way to form Viet sentences? Thanks.