Completions are context sensitive, and are offered according to the syntax mode you are currently typing in. For example, the names of PHP functions will be offered as completions in PHP code.
Possible completions appear in a balloon under the insertion point as you type. To ignore them, just keep on typing. The more you type, the more precise the list becomes. To accept an offered completion, navigate it to it using the up or down arrow keys, then press either return or tab.
To dismiss the autocompletion balloon without performing completion, press Esc.
To turn off autocompletion, choose Coda > Preferences… , click Editor , then uncheck Suggest completions while typing .