That's not a proper thing to say. ✬

She was a rather prim and proper young lady. ✬

We use the symbol “⊂” to denote proper inclusion. ✬

The files are in proper order. ✬

Now that Tom is taking proper medication, he should be able to control himself better. ✬

I'll go get the proper forms. ✬

I'm not the kind of idiot who would climb a mountain in the winter without proper preparations. ✬

Tom didn't follow the proper procedure. ✬

Tom needs proper medical attention. ✬

Tom needs proper medical treatment. ✬