Vim has a built-in spell check that you can enable with :set spell. You can also set the language with :set spelllang= followed by the two-letter code of the language and optionally a dash and the region (e.g., :set spelllang=en or :set spelllang=en-GB).

After enabling the spell checker, you can move between different mistakes with ]s and [s.

I knew about the spell check, I knew Vim highlighted spelling mistakes, and I knew how to move between the mistakes. I usually fix them manually and I never bothered to learn how to make Vim fix them for me. Until today.

If you want to use the output of a command inside your file, you don’t need to exit Vim, run the command, copy the output, return to Vim and paste the contents. You can use :read (or abbreviated to :r) and run a command with !. For example, :r !ls -a will insert the output of ls -a at the current cursor position.

You can also insert the content of another file with :r, except this time you don’t use !, just the file name. For example, :r second_file will insert the content of second_file at the current cursor position.

In Vim, while in normal mode, if you type ~, the capitalisation of the letter under the cursor changes and the cursor is advanced to the right.

You can also change the capitalisation of multiple letters at the same time with g command. Type gU and a movement to make every letter corresponding to the movement to become uppercase. gu makes it lowercase and g~ toggles the case. You can repeat the last character to affect the whole line (guu, gUU, g~~).