If you’re in insert mode:
- Ctrl+d – shift left
- Ctrl+t – shift right
If you’re in normal mode:
- Shift+<< – shift current line left
- Shift+>> – shift current line right
If you’re in visual mode and have 1 or more lines selected:
<– shift selection left>– shift selection right
If you mean just to move backwards a word in normal mode, you can use b to go backwards a word.