Here are two useful keyboard shortcuts for PhpStorm which sound similar, but are quite different:
complete code CTRL + SPACE
will either finish your code if what you typed so far is unambiguous or otherwise offer a list to choose from.
complete current statement CTRL + SHIFT + ENTER will add a semicolon at the end of your statement, no matter where the cursor is.
If you want to train your shortcut skills for PhpStorm or other software, the website shortcutFoo is really helpful and fun to use.