Jag ska träffa Sara i eftermiddag.

Here ska is used to talk about a planned future action. In this sentence, Jag ska träffa Sara i eftermiddag means that meeting Sara is something the speaker intends or expects to do later today.

A useful way to think of it is:

• ska + infinitive = am going to / will / am supposed to

So Jag ska träffa Sara is very close to I’m going to meet Sara.

Because träffa comes after ska, which is a modal-type helper verb. After ska, the main verb stays in the infinitive, which is the dictionary form.

So:

• ska träffa = am going to meet
• not ska träffar

This is similar to English, where we say will meet, not will meets.

After ska, Swedish normally does not use att.

So you say:

• Jag ska träffa Sara
• not Jag ska att träffa Sara

This is the same pattern you get with several common helper verbs in Swedish.

Träffa most often means meet or see someone in the sense of having an arranged meeting or encounter.

In different contexts it can also mean:

• hit a target: Han träffade bollen = He hit the ball
• date / be seeing someone, in some contexts

In this sentence, the natural meaning is simply meet.

Because träffa takes a direct object in Swedish. You meet someone, so the person comes directly after the verb.

• träffa Sara = meet Sara

You do not normally add med here.

This is convenient for English speakers, because it works much like English meet someone.

I eftermiddag means this afternoon or later this afternoon, depending on context.

It refers to the afternoon of the current day, not afternoons in general.

So:

• Jag ska träffa Sara i eftermiddag = I’m meeting Sara this afternoon

This is a fixed time expression. Swedish uses i in several common expressions about parts of the day or nearby time periods, such as:

• i morgon = tomorrow
• i kväll = tonight / this evening
• i natt = tonight / during the night
• i eftermiddag = this afternoon

So here, i is just the normal preposition for this expression.

They are similar, but not identical.

• i eftermiddag = this afternoon
• på eftermiddagen = in the afternoon / during the afternoon

So:

• Jag ska träffa Sara i eftermiddag means specifically this afternoon
• Jag brukar vara trött på eftermiddagen means I’m usually tired in the afternoon

The first points to today; the second can be more general.

Yes. Swedish word order is flexible, but the finite verb still has to stay in the second position in main clauses.

So you can say:

• Jag ska träffa Sara i eftermiddag.
• I eftermiddag ska jag träffa Sara.

Both are correct. The second version puts more focus on the time expression i eftermiddag.

Swedish follows the V2 rule in main clauses, which means the finite verb usually comes second.

In Jag ska träffa Sara i eftermiddag:

1. Jag
2. ska

If you move another element to the front, the verb still stays second:

• I eftermiddag ska jag träffa Sara

That is a very important Swedish sentence pattern.

Yes. That is also natural Swedish.

• Jag ska träffa Sara i eftermiddag emphasizes a plan or intention
• Jag träffar Sara i eftermiddag uses the present tense to talk about a scheduled future event

Both can mean almost the same thing in everyday speech.

Not much grammatically in this sentence. Sara is simply the direct object of träffa.

So:

• Jag = subject
• ska = finite verb
• träffa = infinitive
• Sara = object
• i eftermiddag = time expression

There is no article before personal names in Swedish here, just as in English.

The stress depends on what information is new or important.

Common possibilities are:

• Jag ska träffa Sara i eftermiddag — neutral
• Jag ska träffa Sara i eftermiddag — emphasis on Sara, if that is the new information
• Jag ska träffa Sara i eftermiddag — emphasis on i eftermiddag, if the time matters most

So the sentence can sound slightly different depending on what the speaker is highlighting.