Turn on sticky keys
Sticky keys allows you to type keyboard shortcuts one key at a time rather than having to hold down all of the keys at once. For example, the Alt+Tab shortcut switches between windows. Without sticky keys turned on, you would have to hold down both keys at the same time; with sticky keys turned on, you would press Alt and then Tab to do the same.
You might want to turn on sticky keys if you find it difficult to hold down several keys at once.
Click your name on the top bar and select System Settings.
Open Universal Access and select the Typing tab.
Switch Sticky Keys on.