Jos ehdin, teen raportin valmiiksi ennen kokousta.

If I have time, I will finish the report before the meeting.

Breakdown of Jos ehdin, teen raportin valmiiksi ennen kokousta.

• minä: I
• ennen: before
• jos: if
• ehtiä: to have time; to manage (to do something in time)
• kokous: the meeting
• raportti: the report
• tehdä valmiiksi: to finish

Questions & Answers about Jos ehdin, teen raportin valmiiksi ennen kokousta.

Why is there a comma after Jos ehdin?

Because Jos ehdin is a subordinate clause (an if-clause). In Finnish, when a subordinate clause comes first, it’s normally followed by a comma before the main clause: Jos ehdin, teen...
If you reverse the order, the comma usually comes before the jos-clause: Teen raportin valmiiksi ennen kokousta, jos ehdin.

Why are ehdin and teen in the present tense even though this is about the future?

Finnish commonly uses the present tense for future meaning when the time is clear from context (here: ennen kokousta and the conditional nature of jos). So teen can naturally mean I will do.

What does ehdin mean exactly, and what verb is it?

ehdin is 1st person singular present of ehtiä. It means something like to have time / to make it in time / to manage to do something (in time).
So Jos ehdin implies if I have enough time (or if I manage).

Why isn’t the conditional mood used in the if-clause (why not something like jos ehtisin)?

In Finnish, a real, possible condition often uses the indicative: Jos ehdin, teen... (a realistic plan).
Using the conditional Jos ehtisin, tekisin... typically makes it more hypothetical/uncertain, like If I had time, I would do... (less like a plan, more like a scenario).

Why is raportin in that form, and not raportti or raporttia?

raportin is the total object (singular) form (often genitive-looking). It’s used when the action is seen as completed/result-oriented: do the report (finish it).

• teen raportin = I’ll do the report (as a complete unit)
• teen raporttia = I’ll work on the report / do some of the report (partial, ongoing)

What does valmiiksi add, and what grammar is it?

valmiiksi means finished/ready (to the state of being ready) and emphasizes completion. It’s the translative form (-ksi) from valmis (ready), functioning adverbially here.
So teen raportin valmiiksi is like I’ll get the report finished rather than just I’ll do the report.

Could I say valmiina instead of valmiiksi?

Not with the same meaning.

• valmiiksi focuses on the change/result: make it become ready (finish it)
• valmiina describes a state: being ready
  You could use valmiina in sentences like Raportti on valmiina ennen kokousta (The report is ready before the meeting), but with teen, valmiiksi is the natural choice.

Why is it ennen kokousta (partitive), not something like ennen kokouksen?

The postposition ennen governs the partitive: ennen + partitive. So kokousta is partitive singular of kokous.
This is fixed government: you generally don’t choose the case freely here.

Why are the pronouns minä (I) not included?

Finnish verb endings already show the person clearly:

• ehdin = I have time
• teen = I do / I will do
  So minä is optional and usually only added for emphasis/contrast: Jos minä ehdin, minä teen... (e.g., implying someone else might not).

Can the word order change, and does it change the emphasis?

Yes. Finnish word order is flexible and often used for emphasis/information structure. For example:

• Jos ehdin, teen raportin valmiiksi ennen kokousta. (neutral)
• Teen raportin valmiiksi ennen kokousta, jos ehdin. (main point first; condition added after)
• Ennen kokousta teen raportin valmiiksi, jos ehdin. (emphasizes the deadline before the meeting)

Is Jos ehdin missing something like aikaa (time)? Should it be Jos ehdin tehdä sen?

Nothing is missing. ehtiä can be used without an explicit object when the meaning is general (if I have time / if I manage).
You can also be more explicit if you want:

• Jos ehdin tehdä raportin, teen sen valmiiksi ennen kokousta.
  But the original is natural and concise.

How would I negate this sentence?

You negate the if-clause or the main clause depending on the meaning:

• Jos en ehdi, en tee raporttia valmiiksi ennen kokousta. (If I don’t have time, I won’t get the report finished before the meeting.)
  Often you’ll see raporttia in the negative because negation tends to take the partitive object.