Doing some checking, all I find is the Canadian French keyboard. In that layout, the question mark is produced by Shift-6. On a standard QWERTY keyboard, Shift-6 would produce the caret (^) symbol but not so in the case of…
It depends on the layout of your keyboard. The layout will differ depending on your country.On a British keyboard, shift 7 is the & symbol. Re-ask the question with the missing information (your country).
By the sound of it your keyboard has a damaged contact. If both of the shift keys fail then a new keyboard is recommended. Any attempt to clean the contacts inside the keyboard often makes the problem worse.
The shift key is a modifier key on a keyboard, used to type capital letters and other alternate upper characters. There are typically two shift keys, on the left and right sides of the row below the home row.