Learn Hardcore German: Wahrscheinlich erweitern wir das System nächstes Jahr, wenn die Kosten sinken. - We will probably expand the system next year when the costs drop.

Wahrscheinlich is a sentence adverb (Modaladverb) that comments on the whole clause (“probably”). In German main clauses the finite verb must occupy the second position, so starting with wahrscheinlich pushes the subject (wir) after the verb (erweitern).

Why is the present tense used here even though the action takes place next year?

German commonly uses the present tense for future events when there’s a clear time adverbial like nächstes Jahr. There’s no requirement to form a separate future tense—wir erweitern can mean “we will expand” when paired with a future time expression.

What form is nächstes Jahr, and why is there no preposition like im?

Nächstes Jahr is an accusative time expression used adverbially without a preposition. German allows bare accusative of time (e.g. letzten Monat, nächste Woche). You could also say im nächsten Jahr, but nächstes Jahr is shorter and equally correct.

Why is das System in the accusative case with the article das?

The verb erweitern is transitive and takes a direct object in the accusative. System is a neuter noun, so its accusative form is das System (nominative and accusative neuter share das).

Why does the clause wenn die Kosten sinken come at the end?

Clauses introduced by subordinating conjunctions like wenn (if/when) are subordinate clauses. In German, subordinate clauses are placed at the end of the sentence, and the conjugated verb (sinken) moves to the very end of that clause.

Does wenn here mean if or when?

In German wenn can mean both if and when (in the sense “whenever” or a conditional). In this context it functions as if: “if the costs go down.”

Why is the verb sinken used for costs instead of a verb like fallen?

Both die Kosten sinken and die Kosten fallen are grammatically correct. sinken is a bit more formal or technical (“to decrease, go down”), often used in business or technical contexts. fallen is more colloquial.

What is the typical word order in the main clause after the finite verb?

In a German main clause with verb-second (V2) order, after the verb (erweitern) you usually have Subject (wir), then Object (das System), then Time adverbial (nächstes Jahr). This follows a basic S V O T (Subject-Verb-Object-Time) pattern when no other elements intervene.