Challenge accepted! Words ending with S and T include Welt (world), Sekte (sect), Skelett (skeleton) or Samt (velvet).

And since you asked for some tricky riddles, here’s a classic but elegant one:

It has no lungs, but it breathes; it has no life, but it dies; it has to eat to live, but if you give it water to drink, you’ll kill it.

What is it?

On purpose, if you let it go without a clue!