Only the keys on the left side of my keyboard work. This happened several years ago and I asked if it could be fixed and how to do it. I got an answer. It was as simple as pushing two keys at the same time and my keyboards has worked ever since. Now it has decided to do it again and of course I do not remember what keys I am supposed to key in to fix it. Can you help me please?
It sounds like you have simply turned on Mouse Keys. This is the function where you can use some keys on your keyboard to control the pointer. It is handy if your mouse or trackpad isn't working, or you can't easily use one of those.
Go to System Preferences, Accessibility. Then select Pointer Control on the left. Click Alternate Control Methods at the top. Then turn off Enable Mouse Keys.
You probably turned it on by pressing the Option key five times. TO stop that from happening again, click the Options button next to Enable Mouse Keys. Then uncheck "Press the Option key five times to toggle Mouse Keys."