Vähennämme päästöjä joka kuukausi.

Vähennämme is the 1st person plural present tense form of vähentää, which means to reduce.

So:

• vähentää = to reduce
• vähennämme = we reduce / we are reducing

The ending -mme tells you the subject is we.

Because Finnish usually puts the subject information inside the verb ending.

Here, -mme already means we, so Vähennämme by itself already means we reduce.

You can add me:

• Me vähennämme päästöjä joka kuukausi.

But that usually adds emphasis, like we reduce emissions every month.

This is due to a stem change that happens in many Finnish verbs.

With vähentää, the stem often changes from vähentä- to vähennä- in conjugation:

• vähentää = to reduce
• minä vähennän = I reduce
• me vähennämme = we reduce

So this is just a normal conjugation pattern you need to learn with the verb.

Because päästöjä is in the partitive plural, and that is the natural choice here.

• päästöt = the emissions (nominative plural)
• päästöjä = emissions / some emissions / emissions as an ongoing, not fully bounded object

In Vähennämme päästöjä, the idea is reducing emissions in a general or ongoing sense, not finishing with a complete, total set of emissions. Finnish often uses the partitive for this kind of object.

This is very common with actions that are:

• ongoing
• incomplete
• affecting an unspecified amount

So päästöjä is exactly what you would expect here.

The base form is päästö.

Its forms here are:

• päästö = an emission
• päästöt = emissions
• päästöjä = emissions (partitive plural)

In environmental language, päästö usually means emission, such as carbon emissions or industrial emissions.

Joka kuukausi literally means each month, which is how Finnish says every month.

• joka = each / every
• kuukausi = month

Finnish uses joka + singular noun for expressions like:

• joka päivä = every day
• joka viikko = every week
• joka kuukausi = every month
• joka vuosi = every year

So the singular is normal here.

In joka kuukausi, kuukausi is in its basic singular nominative-looking form.

This whole expression functions as an adverbial of frequency: it tells you how often something happens.

So even though it translates naturally as every month, Finnish does not use a preposition like English does. It simply uses the phrase joka kuukausi.

Yes. Finnish word order is fairly flexible.

The neutral order here is:

• Vähennämme päästöjä joka kuukausi.

But you could also say:

• Joka kuukausi vähennämme päästöjä.

That puts more focus on every month.

The meaning stays basically the same, but the emphasis changes.

Yes.

• Vähennämme päästöjä joka kuukausi.
• Vähennämme päästöjä kuukausittain.

Both can mean We reduce emissions every month / monthly.

The difference is mainly style:

• joka kuukausi = very clear, everyday, straightforward
• kuukausittain = more compact, often a bit more formal or written

Finnish has no separate future tense, so the present tense often covers both present and future depending on context.

So Vähennämme päästöjä joka kuukausi can mean:

• We reduce emissions every month
• We are reducing emissions every month
• and, in the right context, even something like We will reduce emissions every month

Usually, though, this sentence sounds like a habit, policy, or repeated action.

A few things matter here:

• Stress is on the first syllable of each word.
• Double vowels are longer than single vowels.
• ä and ö are separate Finnish vowel sounds, not the same as English a or o.

Roughly:

• Vähennämme → stress on VÄ
• päästöjä → pää has a long ää
• kuukausi → kuu has a long uu

So the rhythm is roughly:

• VÄ-hen-näm-me
• PÄÄS-tö-jä
• JO-ka
• KUU-kau-si

The long vowels in päästöjä and kuukausi are important, because vowel length can change meaning in Finnish.