+----------+------------------------+-----------+---------------------+---------------------------+
| Operator |    Extent modifier     | Full line |       Extent        |          Target           |
+----------+------------------------+-----------+---------------------+---------------------------+
|          | usually related        |           | Text object         | left-right, word,         |
|          | to the line            |           | selection, etc.     | text object motions, etc. |
+----------+------------------------+-----------+---------------------+---------------------------+
| a append | A (at eol)             |           | a 'a' (aw='a word') | b back word               |
| c change | C (from cursor to eol) |           | i innner            | B Block ({...})           |
| d delete | D (from cursor to eol) | dd        | s surround(*)       | e end of word             |
| f find   | F (previous)           |           | t to                | p paragraph               |
| i insert | I (at start of line)   |           | 1,2,3,...           | s sentence                |
| o open   | O (line before)        |           |                     | t tag                     |
| v visual | V (visual line)        |           |                     | w word                    |
| y yank   |                        | yy        |                     | W big_word                |
|          |                        |           |                     | '," quotes                |
|          |                        |           |                     | (,[,{                     |
|          |                        |           |                     | $ end of line             |
+----------+------------------------+-----------+---------------------+---------------------------+

Examples

F"      find previous double quote
vip     visual inner paragraph
ct)     change from cursor to the next bracket
di'     delete in quotes
d2w     delete 2 words
daB     delete a block
cs'"    change surrounding simple quotes to double quotes

See also

:help motion.txt