I want to point out that usually these Vietnamese lesson sites are in the Northern dialect (you can easily tell if it's Northern or Southern dialect when it comes to family terms. For example, ba (meaning father) is Southern and bố (also father) is Northern). My family uses both Northern and Southern dialect. So if you want to know what a word is in Southern dialect, you can ask me. :3
And there are a lot of words on that site that are spelled wrong. If I spelled words like on that website when I used to go to Vietnamese schooling, I'd get F's on my papers.
xd Here's some spelling corrections for lesson 2:
giôø is supposed to be
giờ maáy is supposed to be
mấy
maáy giôø is supposed to be
mấy giờroài is supposed to be
rồi (the ' mark is supposed to be after the ^ mark, but I used an online Vietnamese IME for this)
moät is supposed to be
mộtboán is supposed to be
bốnnaêm is supposed to be
nămsaùu is supposed to be
sáubaûy is supposed to be
bảy taùm is supposed to be
tám möôøi is supposed to be
mườimöôøi moät is supposed to be
mười mộtmöôøi hai is supposed to be
mười haiBa giôØ roài. is supposed to be
ba giờ rồi caùm ôn is supposed to be
cám ơnkhoâng coù gì is supposed to be
không có gì wink Here's another basic Vietnamese learning site. I'm not sure on how clear the lessons are to non-Vietnamese speakers, but the words are spelled correctly on here than on the seasite website.
And if you'd like a real challenge, you can try learning Chu Nom, which is ancient Vietnamese writing. Before the Vietnamese switched to using romanized letters, they used characters similar to Chinese writing. xD