Anyone can learn any instrument, but getting started is the hardest and most crucial part.  These characteristics tend to make beginning easier.

The clarinet is an excellent all-around instrument for the beginning woodwind student.  While it can be difficult to make a tone at first, with a bit of practice, this isn’t too difficult.  Lips and mouths of all kinds are easily adapted to the clarinet.  If your child is having trouble making a tone, it usually comes down to one of two things: 1) Their fingers are not FULLY covering the holes on the instrument, or 2) Their instrument is damaged or misaligned (perhaps imperceptibly at first!).  For this reason it is recommended that students do not have small hands, fingers, or thumbs as they may find it more difficult (but not impossible) to operate the instrument in the early stages.

Personality: Clarinetists are a bit of a mixed-bag, and can even be contradictory. Some tend to be more reserved, but still find themselves being sociable.  They can be the main character, or find themselves just as at home in a secondary role.  Clarinetists are typically goofier than their flute brethren, but less quirky than saxophonists.

Woodwind instruments require a more careful and responsible player than brass instruments as woodwinds can be fairly finicky and do not take abuse well.  Fast fingers are necessary on all woodwinds, but they do not require as much lung and lip strength as brass instruments.