Gretti's response above is good, however before purchasing a new keyboard for your laptop, you might try removing and re-installing the old one.
You can probably google a video on how to do this.
It is good practice to provide make AND model number of units when there are problems.
This may just get the kb working as the keys may be in the same line and remaking contacts might cure the problem.
While removed, turn the keyboard upside down and give a few taps and/or blow out with a hairdryer set to cold and maximum blast to remove any dust etc.
Please advise back on progress.
Good Luck - Keep us posted.