After being on word for a while, when I type an "a" it gives me a "."

[Kimberly]

This is really bugging me. For about 1 month now, when I
am in Word, Iwill be in the middle of typing when the
letters I type turn to jibberish. I try to type the
letter "A" and on the screen it will come up as a
period (.). Please help!