Learn Hardcore Swedish: Jag lägger lerklumpen på drejskivan. - I put the lump of clay on the potter's wheel.

lägga = to lay / to put something somewhere
- it usually takes an object
ligga = to lie / to be lying somewhere
- it describes position, not the act of placing

So:

Jag lägger lerklumpen på drejskivan. = I put / am putting the lump of clay on the wheel.
Lerklumpen ligger på drejskivan. = The lump of clay is lying on the wheel.

This is similar to older English lay vs lie, though Swedish uses the distinction much more clearly in everyday speech.

What form is lägger?

lägger is the present tense of lägga.

Basic forms:

So Jag lägger ... means:

Which English translation fits best depends on context.

Why does lerklumpen end in ?