Pojken spelar i laget.

Because -en is the definite ending here. Swedish often puts the at the end of the noun instead of using a separate word.

• pojke = boy
• pojken = the boy

So pojken means the boy.

In Swedish, definiteness is usually shown by a suffix on the noun. That is why you get:

• pojken = the boy
• laget = the team

So English uses a separate word, but Swedish often attaches it to the noun itself.

The dictionary form is pojke, which means boy.

A common pattern is:

• en pojke = a boy
• pojken = the boy

So when you look up pojken, you would usually look for pojke.

Spela is the infinitive, meaning to play.
Spelar is the present tense, meaning play / plays.

So:

• spela = to play
• spelar = play(s)

In this sentence, the subject is pojken, so you need the finite verb spelar: The boy plays.

No. In modern Swedish, verbs do not change for different persons in the present tense.

So you get:

• jag spelar = I play
• du spelar = you play
• pojken spelar = the boy plays
• vi spelar = we play

The form spelar stays the same.

This is just a difference in preposition choice between the two languages. Swedish says i laget, literally in the team, but the natural English translation is often on the team.

This is very common when learning Swedish: prepositions do not always match English one-for-one.

So:

• spelar i laget = plays on the team

The basic form is lag, which means team.

The forms are:

• ett lag = a team
• laget = the team

So -et here marks the definite form.

Because Swedish nouns belong to different grammatical gender groups, usually called common gender and neuter.

• en pojke → pojken
• ett lag → laget

So:

• nouns with en often take definite -en
• nouns with ett often take definite -et

That is why the endings are different.

The word order is the normal Swedish main-clause order:

subject + verb + other information

So:

• Pojken = subject
• spelar = verb
• i laget = prepositional phrase

This is very similar to normal English word order: The boy plays on the team.

Roughly, it sounds like POY-ken, though the exact Swedish vowels are a bit different from English.

A few pronunciation notes:

• poj sounds somewhat like English poy
• k in pojken is a normal hard k
• the stress is on the first syllable: POJ-ken

If you want to sound more natural, listen closely to native pronunciation, because the vowels are important in Swedish.

Roughly, LAH-get, with the stress on the first syllable.

A few notes:

• a is a broad vowel, not exactly like English a
• g here is pronounced as a hard g
• the ending -et is usually said clearly, though not heavily stressed

So the main stress is on LA-.

Yes, in many contexts the Swedish present tense can correspond to both simple present and present progressive in English.

So spelar can mean:

• plays
• is playing

Which one sounds best depends on context. Without extra context, English often translates it as plays on the team.