「Conditional Verb Form」
「Vcond + ba yokatta・ばよかった」
"I wish~ had done~ "
Vcond ba yokatta expresses the speaker's regret for something he hasn't done. Desu may be added to the adjective yokatta (past form of ii/yoi) to make the speech polite.
Ano hon o kaeba yokatta (desu).
I wish I had bought that book.
Motto yoku kangaereba yokatta (desu).
I wish I had given more thought to it.
Kono koto wa sensei to sōdan sureba yokatta (desu).
I wish I had consulted my teacher about this matter.
Hope this helps!
°˖ ✧◝(○ ヮ ○)◜✧˖ °こゆうきあいはら°˖ ✧◝(○ ヮ ○)◜✧˖ °