Jag tog bort löven och såg att en gren låg på stigen.

Because ta bort is a particle verb in Swedish. The basic verb is ta, but together with bort it means remove or take away.

So:

• ta = take
• ta bort = remove / take away
• tog bort = removed / took away

In this sentence, tog is the past tense of ta.

Because löven is the definite plural form of löv.

The forms are:

• ett löv = a leaf
• löv = leaves
• löven = the leaves

So the sentence uses löven because it refers to a specific set of leaves, not just leaves in general.

This is a very common point of confusion.

Even though both end in -en, they come from different noun patterns:

• en stig → stigen = the path/trail
• ett löv → plural löv → definite plural löven = the leaves

So -en does not always mean the same thing by itself. In Swedish, you have to look at the whole noun pattern, not just the ending.

Here:

• stigen = singular definite
• löven = plural definite

Here att introduces a subordinate clause, similar to that in English:

• såg att en gren låg på stigen

This means the speaker saw/noticed that a branch was lying on the path.

In English, that is often optional:

• I saw that a branch was on the path.
• I saw a branch was on the path.

In Swedish, att is very natural here and is normally kept.

Because after att, you are in a subordinate clause, and Swedish word order changes.

In a main clause, Swedish usually has verb-second word order:

• Jag såg ...

But in a subordinate clause, the subject usually comes before the finite verb:

• att en gren låg på stigen

So:

• main clause: Jag såg
• subordinate clause: att en gren låg

That is why en gren låg is correct here.

Because en gren introduces something new into the story.

In Swedish, just like in English, an indefinite form is often used when something is mentioned for the first time:

• en gren = a branch

If the branch had already been known or previously mentioned, grenen might be used instead:

• grenen = the branch

So en gren feels natural because the branch is being introduced at that moment.

Swedish often prefers a position verb where English might simply use was.

Here ligga means lie or be lying, and its past tense is låg.

So en gren låg på stigen literally describes the branch as lying on the path.

This is very natural in Swedish. Compare:

• boken låg på bordet = the book was lying on the table
• nycklarna låg i väskan = the keys were in the bag

Using vara would be less specific. Låg tells you the branch was resting there in a lying position.

Because på is the normal preposition for something located on a path, road, trail, table, floor, and so on.

So:

• på stigen = on the path / on the trail

Using i would suggest being inside something, which does not fit well here.

Swedish commonly uses på with surfaces and routes:

• på bordet = on the table
• på golvet = on the floor
• på vägen = on the road
• på stigen = on the path

They are all irregular past tense forms:

• tog → infinitive ta
• såg → infinitive se
• låg → infinitive ligga

So the full structure is:

• Jag tog bort ...
• och såg
• att en gren låg ...

These are very common verbs, so it is worth learning their irregular past forms early.

Usually, yes: it naturally suggests a sequence in the narration.

The sentence gives this flow:

1. Jag tog bort löven
2. och såg att en gren låg på stigen

So the most natural reading is that the speaker removed the leaves and then noticed that there was a branch on the path.

However, och itself is just and. It links the two past actions; the exact timing comes mostly from context and from how we normally understand the situation.