The good news is that very few people can’t be hypnotised. Hypnosis is an enjoyable natural state of awareness. As such, hypnosis is a state most people experience often without ever noticing. Unfortunately there isn’t an alarm that goes off in your mind every time you enter hypnosis.
The only people that can’t be hypnotised are those that don’t want to be, those that aren’t intelligent enough and those that have trouble communicating with the hypnotist.
People that don’t want to go into Hypnosis.
There are many reasons for not wanting to go into hypnosis, most of which have something to do with fear.
The biggest fear most people have to do with hypnosis is that they’ll lose control of themselves and embarrass themselves. This idea usually comes from watching stage hypnosis. What these people don’t realise is that stage hypnotists only ever use volunteers. Stage hypnotist dare not use anyone that isn’t happy to be silly on stage or the person on stage will refuse to carry out the suggestion and the show will fail. People will only do what they consider reasonable and pleasing while in hypnosis.
Those that aren't intelligent Enough.
Those that have trouble Communicating.
I’ve worked with a number of people that are severely hearing impaired. I found it very hard going and so did my poor clients, but it did work. It took more sessions because I to talk (shout) slower and watch carefully for understanding, but the persistent hearing impaired clients definitely won.
Those that don’t speak the language that the hypnotist speaks will also obviously not be able the directions into hypnosis. The remedy is simple; find a hypnotist that does.
Those that can’t communicate at all can’t be hypnotised as they just can’t follow the directions or learn the directions for themselves.
Other than these three types of people, everyone else can be hypnotised, usually very quickly and very easily.