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.

of the "Nautilus" section
of the Mandelbrot SET.
The Big Bang Theory Season 12, Episode 19

Oh. Now, what about our 3-D chess SET?
The Big Bang Theory Season 10, Episode 10

If you wait for us
to SET up the time machine...
The Big Bang Theory Season 1, Episode 14

once a year, we SET aside
a day to celebrate
The Big Bang Theory Season 5, Episode 15

we can SET up
a factory-grade laboratory for you.
Breaking Bad Season 4, Episode 8