How do you use a guitar tuner?

[the freak]

How the heck do you use a guitar tuner?Do you put the hole thingy over the tuning knobs?Or do you even attach it to the guitar at all?Please help quickly!

[flashpig]

If it is an electric guitar, you plug it into the guitar like you would the amplifier.

If it is an accoustic guitar, most of the tuners have microphones within them, you play the note and it'll tell you whether the note is sharp or flat.

Alternatively, tuning pipes; play the note on your guitar and compare it to the note produced by blowing into the relative pipe, then by ear determine the need for retuning the string.

[stevie21]

The first type, mentioned by flashpig have a display like this, telling you to tune the string up or down:
http://tinyurl.com/6p95s
I have one like this & I can either sit it next to my guitar and play a note (the tuner has a microphone which picks up the note) or I can plug my guitar into it.

There are also tuners which have an attachment which fits over the tuning peg and tightens and loosens the strings for you to tune the guitar. Even less effort!
This type looks more like this:
http://www.actiontuners.com/