Under a spreading chestnut tree

which syllables are unstressed?

UNder A SPREADing CHESTnut tree

capital letters = stressed

is this right?

Say it aloud. Which syllables are stressed, which unstressed?

Katherine is wrong.

Okay, so what I think it is is: UNder A chestNUT tree, but I'm most likely wrong

Nope.

Un DER a SPREAD . . .

Take it from there.

Un DER a SPREAD ing chest NUT tree

Nope. un DER a SPREAD ing CHEST nut TREE.