Vim commands I always forget

Format Lines - gq

gq{motion}
{Visual}gq
gqq
...
I'd suggest you check out :help gq and :help gw.

Also setting textwidth (tw) will give you auto line break when exceeded during typing. It is used in gq too, though if disabled gq breaks on window size or 79 depending on which comes first.

:set tw=80

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