The best way to learn proper English is to read news report, and watch news on TV. Watching TV shows is a great way to learn casual English, slang words, understand culture reference and humor. If you have already watched these shows then you may recall the words used in the following dialogs.

Look at you,
you look so INNOCENT like this.
Money Heist Season 3, Episode 4

Myrcella is a sweet, INNOCENT girl
and I don't blame her at all for you.
Game of Thrones Season 2, Episode 5

I'm just an INNOCENT woman...
The Big Bang Theory Season 4, Episode 22

You saved one INNOCENT.
Game of Thrones Season 3, Episode 10

I mean, they're so INNOCENT,
and you know how guys are.
The Big Bang Theory Season 9, Episode 21