J for jaa

J for jaa
じゃあ
じゃ=ja
あ=a
jaa means well(then)
ja arimasen = am/is/are not
じゃありません
じゃ=ja
あ=a
り=ri
ま=ma
せ=se
ん=n
wakarimasu means I understand
wakarimasen means I don't understand
if you replace su with sen in the end of word it means negation.
hai, wakarimasu
yes, I understand
Iie, wakarimasen
no, I don't understand