枕が合わないって英語でなんて言うの？

To fit is the way to talk about how things such as clothes or objects mold to your body. I hope that this helps :)

You are unhappy with your pillow because it is lumpy or too hard or soft etc. If it's really uncomfortable you could use any of the example sentences to express your displeasure.

Instead of saying that a pillow 'doesn't fit' it would be more correct in English to say that the pillow is 'uncomfortable'. Uncomfortable is when something does not feel right or may feel awkward on our body and therefore you may find it hard to sleep.

When your pillow doesn't seem to fit you and as a result makes you feel uncomfortable; then you may express this in the following ways: -My pillow is not comfortable. -My pillow makes me feel uncomfortable because it does not seem to fit my neck

suit someone - to be right for someone or to match someone's preferences the right one for - the perfect match

"My pillow makes my neck hurt." Pillow makes - the pillow is what is causing hurt. Hurt - you could also say sore, tight, stiff, etc. "My neck is always in pain after using this pillow!" Always - this is something that happens every time you use the pillow. In pain - maybe the pillow causes your neck to be stiff, tight, etc, but you feel pain, discomfort when you wake up. Using - meaning the pillow is holding your head. That is the pillows use.

"My pillow is very uncomfortable to sleep on. It hurts my neck." This gives an indication that the cause of your sore/injured neck is due to your pillow. By saying it is uncomfortable to sleep on you are indicating it caused you a restless night, and means in the morning you woke up with a sore neck. "My pillow is no longer suitable, it gives me neck pain. " This gives an indication that you need to buy a new pillow. The reason being is because it is causing your neck pain, therefore it has lost its purpose of helping you rest at night. "My pillow is giving me neck pain." This is a simple way of informing people you are currently in pain because of your pillow.