A twelve string guitar can add some extra jangle and shimmer to your guitar playing and give you a slightly fuller (but different) sound than a six string guitar. You play them both the same way - but on a twelve string there are 6 pairs of strings tuned either in octaves (different gauge strings) or in the case of the 1st and 2nd string pairs (e and b in standard tuning) unisons. The resulting sound is similar to applying a chorus effect to a six string guitar using electronics. Notes and chords are played the same.
So let me list the advantages and disadvantages of a twelve string guitar over a six string guitar.
- The sound. With twelve strings, you get a potentially fuller more robust sound, although it may be described as more chimey than boomey. You can derive a unique sound from a twelve string guitar that you may like, particularly for certain styles of music or certain songs.
- Twice as many strings. With twice as many strings you will spend more money on replacement strings and it will take at least twice as long to change the strings and you have 12 strings to keep in tune. That's actually three in one.
- Wider neck may make it harder to reach certain chords. In order to fit 12 strings within the width of the neck (fretboard) of the guitar, the neck of a twelve string will be wider than most six string guitars and there will be a greater distance between the low E pair and the high e pair. This will mean a greater stretch will be required to play certain chords.
- Heavier thicker neck. In order to support the increased string tension of 12 strings, a twelve string guitar will have a heavier, usually thicker neck which will make the guitar itself heavier but also may be less comfortable to play for some people.
- Harder to fret strings. Because you are pressing down two strings on a twelve string for every one string on a six string, as you can imagine, more pressure will be required to press the strings against the frets. This will be particularly evident when playing barre chords where you may be barring all twelve strings at once.
- A standard capo may not be wide enough. They do make capos for twelve string guitars. But if you have a capo for your current six string guitar it might not work with a twelve string.
As far as using a twelve string guitar with only six strings - it can be done but makes no sense whatsoever! To learn why - read this 12 to 6 strings on a 12 string guitar - why it's a bad idea
I use a twelve string guitar to play a few songs in my repertoire that just seem to sound better on a twelve string guitar. I like the way it sounds for those songs. I don't find it as comfortable or enjoyable to play as my six string guitars, so it stays in the case most of the time.
If you like the sound of a twelve string guitar, try playing one at a music store or a friend's. See how it feels. Compare different brands - some are easier to play than others but may not sound as good as the ones that are harder to play. Don't buy a twelve string guitar without trying it out.
If you do purchase a twelve string guitar, don't be discouraged if at first it is very tiring on your fretting hand to play. Eventually you will build more strength and it will become easier (though never as easy to play as a six string). Also, in time, you will adjust to the wider string spacing.
I owned many six string guitars and became proficient playing them before I ever acquired a twelve string guitar. If I could only have one, it would definitely be a six string. I feel that it is more versatile in terms of the style of play that it affords and for many other reasons. That is just my opinion, but consider that there is probably a reason why relatively few guitarist even own a twelve string guitar.
For your next guitar - you may want to consider a really good quality six string that is a good fit for your hand size and style of play. Later as you progress in your playing ability and start getting bored playing the same guitar all the time - you can add a twelve string guitar to your arsenal.
Have fun on your journey.