I sleep in middle. You sleep in outside. Mummy sleeps in inside

Question

My son wanted to change the position with me.

"I want to sleep here." He said.

"It's Okay. Becareful not to fall out the bed. I sleep in middle. You sleep in outside. Mummy sleeps in inside."

(Beside my wife is a wall. So I let him know it was inside.)

I am a bit confuse the preposition for the people in the bed.

What adjective should I use?

Answer 1

In your situation inside and outside work well enough and generally would be understood.

One better alternative (which I personally would use) is using relative directions of left and right. This is more adaptive as it works in all situations, (eg when there is no wall) and eliminates the possible confusion of inside=indoors outside=outdoors

It also has the added bonus of providing an opportunity to teach your son to learn/use direction too :)

You sleep on the left.

I sleep in the middle.

Mummy sleeps on the right.

Answer 2

If one side of the bed is bordered by a wall, then "inside" and "outside" are natural and appropriate expressions in English - I don't think there are better ones. There are other ways to refer to these positions, but they are not better.

Note that you need the article "the" in all three cases.

"Inside" and "outside" use the preposition "on", while "middle" uses "in".

So

You sleep on the outside (of the bed).

I sleep in the middle.

Mommy sleeps on the inside.