I dont speak french, so I have never used that word in a sentence ;-))
The last time I used the word "piquant" in a sentence would be in this sentence. Previous to that, I never used it. :)
I don't remember; I use it occasionally.
I used it just yesterday. I gave my son a choice between two equally unlikable alternatives.
In the face of his mounting indecisiveness, I said, " Hurry up kid, piq-uant!!"