How do you use the question mark

https://support.microsoft.com/en-ca/kb/258824 - I suggest you check out this article - or you can google yourself - How do I change my Keyboard Mapping? and then see what comes up.
I would appear that you have somehow setup something on those keys - e with an accent above is most likely French

When you were typing something you probably hit the left shift key along with ctrl. Hold down the left shift and ctrl for about 2-4 seconds and you should get your question mark back.

To make it so it never happens again, go to control panel / region and language / keyboards and languages / change keyboards. Remove every language except for English (us) or whatever region you want to use. Before you accept verify that your keyboard is on your preferred language before you do this. check and make sure you are getting the proper slash when you push slash, to change it if you're not getting the slash use the (left ctrl + left shift for 3-4 seconds) if that doesn't work then try alt and left shift.

No button does that, nor a CATALOG command. But do check in the CATALOG (2nd 0).

Blue functions are common now but usually only on laptops. They are accessed via a blue button normally labelled Fn down in the left corner near CTRL and SHIFT. Hold the Fn button and press the desired button to acheive the function.

While listening to the message, press the delete button (just above the message number, marked with a circle with a slash through it).

2 wires plus ground needs a stereo 1/4 plug. Don't know Mark 4, but Mark 3 has 2 button fs with 3 wires plus ground. Schematic here: http://el34world.com/charts/Schematics/files/peavey/peavey_mark_3_bass_with_pa.pdf
shows 3 wires plus ground. Stereo plug does not have enough connections, only ground plus 2 wires.
Count the pins of socket and find DIN plug with proper pin-out for socket. Search google for DIN plugs.

Depending on setting, assuming that the keyboard is set to United States, the ? and / key are next to the shift key on the right side, bottom row. For a question mark hold down the shift key.

I hope this is helpfull

Press the flash button (right-arrow on the control panel, marked with a lightning bolt) repeatedly to cycle through the flash settings. To turn the flash off, select Off, marked by a lightning bolt in a circle with a slash through it.

Don't forget to turn it back on when you're done.

Try checking the language settings in the keyboard settings?

sometimes if its set to U.S or another language some of the keys may do different things

The best solution may be to re-define the named columns, or to add new names to multi-column arrays, then use the VLOOKUP function.
Note that the "indexed" named cells must be sorted by the index column.

Test (this is a 2 year old question)... Please ignore ths following. The plus symbol does not display.
Upper key plus symbol displays:
Right plus symbol on number pad displays:
[Shift] Right plus symbol on number pad displays:
[Alt] [4] [3] displays:
slash/slash/plus displays: //
slash/plus/slash displays: / /
Plus Plus Plus displays:
upper Plus Plus Plus displays:
Shift Right plus plus plus displays:

end of plus test.. thanks.