My macbook air has swapped keyboards

Solved!! And it took the kind suggestions of all of you, so many thanks. Here's what seems to have worked:

I rummaged around in my saved outdated computer stuff and found a raggedy old PC keyboard with a USB connection. Of course, that meant I had to also use my little connector/converter for thunderbolt etc in order to attach it. Did so and noticed a tiny little "suitcase" icon with a capital letter A light up.

What?? Could that mean caps lock was on, even if the US keyboard (as of late last night) now appeared to be the default for the Mac? Maybe this morning's unsuccessful log in was due to caps lock being on now? (It was not on when we chatted earlier--I checked.)

So, I clicked the suitcase icon and tried the password again.

FINALLY!!! I'm in.

Okay, I greatly appreciate the advice and thank you all. With any luck, I can handle it from here.

I may have to buy an external keyboard, since I don't have one and I am practically the only one in the family with a mac. Daughter has a mac but lives nearly two thousand miles away. My friends are PC lovers as well.

This is on the list of things to try. Hoping for cheaper fixes first.

Thank you for your quick reply. (1) I did consider an external keyboard. The only one I had on hand was a blue tooth one and I could not switch bluetooth on for the computer without logging in. If I have to, I could buy an external keyboard, but hope to solve the problem without that if I can.

(2) I actually did find the first two of your links a couple of days ago and followed them for information. I believe the trouble started when I was trying to type an e aigu and an e grave on my computer. I am sure it is something I did.

(3) I looked through your third link (and will keep it as a nice resource) and saw the Canadian French keyboard which I had not considered. The swapped keyboard is definitely an AZERTY keyboard, though, not a QWERTY keyboard because when I tried to type, the letters Q and A were swapped.

Good ideas, though. If I could just figure out how to enter my password, I think I could probably solve the keyboard swap now.

Thank you for your reply, Tom.

(1) Q and A are swapped; the W and Z are swapped and I had to type a semicolon to get an M. I was answering some emails prior to the crash.

(2) I did try those combinations and they did not work. As I think about it, perhaps an error was made on the other portion of the password. I need to try them again and watch for my capital letters, etc. I was worried I would get locked out permanently if I did though.

(3) The suggestion on system settings is a good one. That had also been tried when I called into Apple Support. At that time we had not identified the possibility of a French keyboard. The swapped keyboard did not show up when we did that either. Nothing was there except the US one.

That's the reason I am so buffaloed here. I had done due diligence prior to calling Apple Care and again before I posted here. I wish I had been able to finish talking to Apple Care, but had to leave for an appointment. I will call back if necessary but hoped we had an easy fix for this. Am afraid issue is larger than it appears.

I don't know what symbol was typed, because the password is hidden unfortunately. All I can see are the little circles for the symbols, then a wait while hoping I got the stupid password right, then the let down when the circles dance and taunt me.