Some simple tests to establish whether you are:
1-First, connect yourself to an amplifier via a standard guitar cable. You should have a hole somewhere for the plug to go into. Switch on amp. Does sound come out? If yes, proceed to step 2.
2-Examine yourself for knobs. If you twist a knob, does the volume change or the sound become brighter/darker? If yes, proceed to step 3.
3-If anybody cares about you (and you are indeed a guitar), there should be a wooden box around that you fit into called a 'case'. Find case, and see if you fit in. By now, if you could reply 'yes' to all the steps mentioned, I am fairly certain you are one, yes. But let's make SURE about this. Proceed to step 4.
4-Do you often get picked up by people (or a person) and hung around their necks while they put a plug in your hole then tickled across the chest while having your neck fondled? If yes, I am almost DEAD certain you are one. Anyhow, for just in case, proceed to final step.
5-If while being slung around a person's neck with the plug in your hole and having your chest tickled and neck fondled, do you often break your g-string? Then you are definitely a guitar. Not only that, but you are probably owned by a more-than-decent Blues player.
Identity Crisis: SOLVED
You may thank me with gifts of reefer, single-barrel whisky, or a series of deposits into my bank account, whichever you prefer