vim-verbs.txt

c => change
d => delete
y => yank
s => deletes the character under the cursor and then enters Insert mode

i => inside
a => around
t => till a character
f => till a character (including character)

w => word
s => sentence
p => paragraph
b => block / parenthesis
t => tag

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diw => delete inside word
cis => change current sentence
ci" => change inside "
ci' => change inside '
ci) => change inside )
ci( => change inside (