Keyboard won’t print some letters

Per Apple: You may have accidentally set an option that changes how your keyboard operates.

• Choose Apple menu  > System Preferences, click Accessibility , click Keyboard, then click Hardware. Make sure Slow Keys is turned off. If Slow Keys is on, you must press and hold a key longer than usual before it’s recognized.
• Choose Apple menu > System Preferences, click Accessibility, click Pointer Control, then click Alternate Control Methods. Make sure Mouse Keys is off.
• Choose Apple menu > System Preferences, click Keyboard , then click Input Sources. Select “Show Input menu in menu bar.” Open the Input menu, then make sure the correct keyboard layout is selected.

Or the keyboard is failing, or some debris is blocking the action of certain keys. To clear debris, invert, and shake gently. Then examine the gaps between the keys, looking for hair or other objects, and remove any found.

Have you tried another keyboard? Maybe problem with the one you are using.

When's the last time you cleaned or down out your keyboard?

Make sure Mouse Keys is disabled.