Learn Hardcore Norwegian: Bladene ligger på bakken om høsten.

Bladene is the definite plural form of blad (leaf), so it means the leaves. In Norwegian you add -ene to make a masculine noun both plural and definite. Without -ene, blader would simply mean “leaves” in an indefinite sense.

Why do we use ligger here instead of er?

In Norwegian you use ligge to describe something lying or resting on a surface—where it is positioned horizontally. Ligger is the present tense of ligge. While you could use er (to be) for location, liggere gives a clearer sense of “lying on” (just like English “lie on”).

What does på bakken mean, and why is the preposition på used?

På bakken translates as on the ground. The preposition på is used for “on” surfaces in Norwegian, similar to English. Bakken is the definite form of bakke (ground, hill), so the phrase literally means on the ground.

Why is it om høsten and not i høsten?

Om høsten means in (the) autumn when talking about something habitual or recurring (every autumn). Norwegian uses om with seasons in that sense. On the other hand, i høst (without the definite article) means this autumn, referring to the current or a specific season.

Can you omit the definite article and say om høst?

No. When using om to talk about seasons in general, you need the definite form: om våren, om sommeren, om høsten, om vinteren. Om + indefinite season (om høst) would sound ungrammatical.

Could we start the sentence with Om høsten, like Om høsten ligger bladene på bakken? What changes?

Yes. Norwegian follows the verb-second (V2) rule. If you place the time expression Om høsten at the beginning, the verb ligger still has to be in second position, followed by the subject bladene. So Om høsten ligger bladene på bakken is correct and puts extra emphasis on the time frame.