How to pronounce 天真 in Cantonese (4 out of 5):

係啦 最天真嘅時候
Yes, when you're most naive.

Cantonese Sentence Breakdown

hai6
(Cantonese) to be
to connect
to relate to
to tie up
to bind
to be (literary)
to involve
relation
relationship
consequence
yes
indeed
right
la5
“now”, with an connotation of doubt
surprise
disapproval
zeoi3
most
the most
-est (superlative suffix)
exceedingly
extreme
天真 tin1 zan1
naive
koi3
indignant
generous
to sigh (with emotion)
時候 si4 hau6
time