Learn Finnish: Hallitus ennustaa nopeaa talouskasvua. - The government forecasts fast economic growth.

Using tulee ennustamaan changes the meaning! It would mean the government will make a forecast at some future time. In this sentence, the government is making the forecast right now in the present tense (ennustaa), even though the growth itself is what belongs to the future.

Why is the object nopeaa talouskasvua in the partitive case?

The verb ennustaa (to forecast or predict) expresses an irresultative action and therefore takes a partitive object. When you predict something, the action doesn't physically complete or alter the object. Additionally, talouskasvu (economic growth) is an abstract, uncountable concept, which naturally aligns with the partitive case.

If we wanted to express the outcome of this forecast using the lesson's grammar ('The economy will grow fast'), how would we build it?

You would use the analytical future construction with the verb kasvaa (to grow). The structure is tulla + 3rd infinitive illative: Talous tulee kasvamaan nopeasti. Notice that we had to change the adjective nopea (fast) from the original sentence into the adverb nopeasti (quickly) to describe the action.

Is there a reason talouskasvua uses the nominative talous as its first part rather than the genitive talouden?