Takin sauma on auki, joten vien sen ompelijalle.

Because takin is the genitive singular form of takki.

In this sentence, takin sauma literally means the coat's seam or the seam of the coat. Finnish often uses the genitive to show possession or close relationship.

So:

• takki = coat
• takin = of the coat / the coat's

There is also consonant gradation here:

• takki → takin

The kk changes to k in this form.

Sauma means seam.

It refers to the stitched line where pieces of fabric are joined together. In this sentence, takin sauma is the seam of the coat.

So the first part, Takin sauma on auki, is talking about a clothing repair problem.

Finnish often uses the structure:

• on = is
• auki = open

So on auki literally means is open.

This is a very common way to describe a state or condition in Finnish. It is used in many everyday expressions, for example:

• Ovi on auki = The door is open
• Kauppa on auki = The shop is open

In your sentence, sauma on auki means the seam has come open / is split open.

No. Auki is broader than that.

It can mean:

• physically open: ovi on auki = the door is open
• open for business: kauppa on auki = the shop is open
• split/opened up: sauma on auki = the seam is open
• undone/unfastened in some contexts

So here it does not mean open like a door; it means the seam has opened up.

Joten means so, therefore, or thus.

It introduces a result or consequence:

• Takin sauma on auki, joten vien sen ompelijalle.
• The seam of the coat is open, so I’m taking it to a tailor.

It connects the two ideas:

1. There is a problem.
2. Therefore, an action follows.

A learner may also see words like siksi or niin, but joten is a common written and spoken way to mean so/therefore in this kind of sentence.

Vien is the first person singular present tense of viedä, which means to take or to bring depending on perspective.

So:

• minä vien = I take / I will take

Finnish usually leaves out the subject pronoun minä because the verb ending already shows who the subject is.

Here:

• vien = I take / I’m taking / I’ll take

Since Finnish has no separate future tense, the present form often covers future meaning when the context makes it clear.

Finnish does not have a separate grammatical future tense like English.

The present tense is often used for:

• present actions
• near future
• planned future actions

So vien sen ompelijalle can mean:

• I’m taking it to the tailor
• I’ll take it to the tailor

The context tells you it is about a next action resulting from the problem.

Sen means it here, and it refers to takki — the coat.

Why sen?

Because it is the object form used here for a total, completed action. In many basic explanations, learners are told that sen is the genitive/accusative-like object form of se.

Compare:

• se = it
• sen = it / its / of it, depending on context

In this sentence:

• vien sen ompelijalle = I’ll take it to the tailor

The idea is that the coat is being taken as a whole object.

Grammatically, sen could in theory refer back to something mentioned earlier, but in this sentence the natural interpretation is takki.

Why?

Because you normally take the coat to the tailor, not just the seam. The meaning of the situation makes that clear.

So Finnish speakers understand sen here as the coat.

Because ompelijalle is in the allative case, which often means to, onto, or to the possession of someone.

The ending -lle is very common when something goes to a person:

• annan kirjan opettajalle = I give the book to the teacher
• vien sen ompelijalle = I take it to the tailor

So:

• ompelija = tailor / sewer / seamstress
• ompelijalle = to the tailor

Not always exactly.

Ompelija comes from the verb ommella, meaning to sew. So ompelija is literally someone who sews.

Depending on context, it can be translated as:

• tailor
• dressmaker
• seamstress
• sewer

In this sentence, tailor is a natural English translation because it is someone you take clothes to for repair.

Yes, it is often implied by context.

English often says:

• My coat’s seam is open

But Finnish can simply say:

• Takin sauma on auki

If the speaker is obviously talking about their own coat, there is no need to say minun takkini.

Finnish often leaves possession unstated when it is already clear from context.

If you wanted to make it explicit, you could say:

• Minun takkini sauma on auki.

But that sounds more explicit and is not always necessary.

The word order is fairly neutral and natural.

First clause:

• Takin sauma = topic / subject phrase
• on = is
• auki = open

Second clause:

• joten = so / therefore
• vien = I take / I’ll take
• sen = it
• ompelijalle = to the tailor

A very literal breakdown is:

• The coat’s seam is open, so I take it to the tailor.

Finnish word order is flexible, but this version is standard and easy to understand.

This sentence is closer to standard written Finnish, though it is also perfectly understandable in speech.

A more casual spoken version might look different, for example:

• Takin sauma on auki, joten mä vien sen ompelijalle.
• or even with other spoken-style changes depending on dialect

What makes your original sentence feel standard is especially:

• no subject pronoun before vien
• the use of joten
• fully standard forms like ompelijalle

So it is a very good model sentence for learners.