"My in-laws wear blue hats" should be accepted.
Wouldn't that require topi-topi to indicate plural?
Nothing in the sentence indicates gender therefore my father in law should also be correct.
Why not use "ayah mertua" to refer to father-in-law when mertua refers to both father- and mother-in-law? My mother-in-law also wears blue hats LOL
Could this also translate as 'my father/mother-in-law uses a blue hat'?
It's a bit of a silly sentence, but I'm trying to get my head around how the verb memakai can mean both 'to wear' and 'to use'.