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.

I HAVE always found that
to be the purest of motivations,
Game of Thrones Season 2, Episode 5

I'm not saying
you don't HAVE attractive qualities.
The Big Bang Theory Season 6, Episode 8

I would HAVE remembered.
Vikings Season 1, Episode 2

you might HAVE been my child.
Game of Thrones Season 4, Episode 7

And that was the year
we didn't HAVE one.
The Big Bang Theory Season 12, Episode 13