A window has a job: to let you see out.

So the job needs a material that is see-through.

Glass is see-through. So glass suits a window.

A glass window. Glass is see-through.

A raincoat has a job: to keep the rain off you.

Plastic keeps water out. So plastic suits a raincoat.

But paper soaks up water. So paper does not suit a raincoat.

Does the material suit the job? Plastic keeps water out: it suits a raincoat. Paper soaks up water: it does not.

A pillow has a job: to be soft under your head.

Cotton stuffing is soft. So cotton suits a pillow.

Four jobs, the property each job needs, and a material that has it.