Föreningen startar en insamling.

Because -en at the end makes the noun definite.

• förening = an association / a club / an organization
• föreningen = the association

In Swedish, the definite article is often attached to the end of the noun instead of being a separate word like the in English.

So:

• en förening = an association
• föreningen = the association

Startar is the present tense of starta, which means to start, to begin, or sometimes to launch.

So:

• starta = to start
• startar = starts / is starting

In this sentence, startar can often be translated naturally as either:

• starts
• is starting
• launches

Swedish present tense often covers both the simple present and the English present progressive, depending on context.

Because insamling is a common gender noun, also called an en-word.

In Swedish, nouns usually belong to one of two genders:

• en-words
• ett-words

insamling is an en-word, so in the indefinite singular you say:

• en insamling = a collection / a fundraiser / a fundraising drive

If it were definite, it would become:

• insamlingen = the collection / the fundraiser

Insamling literally means collection, but in real usage it often means a fundraiser, fundraising campaign, or fundraising drive.

So en insamling can refer to collecting:

• money
• clothes
• food
• signatures
• other donated items

The exact English translation depends on context. If the context is charity, fundraiser or fundraising campaign is often the most natural translation.

Because Swedish usually expresses the by adding a definite ending to the noun.

Compare:

• förening = association
• föreningen = the association

This is one of the biggest differences from English. Instead of saying a separate word before the noun, Swedish often puts the definiteness at the end.

However, Swedish can also use a separate determiner in some cases, especially with adjectives:

• den stora föreningen = the big association

But in your sentence there is no adjective, so föreningen by itself is enough.

Yes. This is very standard Swedish word order:

subject + verb + object

• Föreningen = subject
• startar = verb
• en insamling = object

This is the most basic sentence pattern in Swedish, just like in English:

• The association
  • starts
    • a fundraiser

If you move another element to the beginning, Swedish still keeps the verb in second position:

• I dag startar föreningen en insamling. = Today, the association is starting a fundraiser.

That verb-second pattern is very important in Swedish.

Not usually. Starta is the more natural verb here.

• starta en insamling = start / launch a fundraiser
• börja often means begin, but it is less natural with things like campaigns, projects, or drives in this kind of context

So Swedish commonly says:

• starta en kampanj
• starta ett projekt
• starta en insamling

Using börja would sound less idiomatic here.

A rough guide is:

FUR-eh-ning-en

A few useful points:

• ö is not the same as English o
• förening is pronounced roughly FUR-eh-ning
• föreningen adds the final -en

If you want to break it up:

• fö
• re
• ning
• en

The g in -ing is pronounced clearly in Swedish, unlike in English -ing endings.

The dictionary forms are:

• förening = noun
• starta = verb
• insamling = noun

The sentence uses these forms:

• föreningen = definite singular of förening
• startar = present tense of starta
• en insamling = indefinite singular of insamling

So if you were looking the words up in a dictionary, you would usually search for:

• förening
• starta
• insamling

Yes. Förening is a flexible word and can mean:

• association
• club
• society
• organization

The best translation depends on context. For example:

• a sports club
• a local community association
• a nonprofit group

So in this sentence, föreningen could refer to many kinds of organized groups, not only a formal association in the narrowest sense.