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.

In some cases,
the ends JUSTIFY the means.
Westworld Season 2, Episode 9

lt's amazing the stories you tell
yourself to JUSTIFY it.
Breaking Bad Season 4, Episode 4

Let's both of us stop trying
to JUSTIFY this whole thing
Breaking Bad Season 4, Episode 6

Is that how you can JUSTIFY
what you've done to him?
Westworld Season 2, Episode 7