Keyboard language reset I can't login

Here’s a good vid which gets you to the language settings How To Change Language On MacBook

Once to correct the setting you can add the keyboard option to show the keyboard options in your menu bar so you can toggle between the different languages if you are bilingual or you share your system with some one who is.

As long as you remember the letter keys they should still let you log into your system. If not you can try resetting the SMC but I often find there’s something more going on. Is this a used system?