Impersonal predicates with a da-clause

When people talk about society they often state an opinion or a fact without saying whose it is: It is possible that taxes will rise. It is necessary that the state invests in schools. It is well known that young people are leaving. Serbian has one standard frame for this, and you already know one instance of it: treba da (Treba da glasamo - We should vote).

The frame is: adjective in the neuter form + je + da + a full clause. The English 'it' has no equivalent - Serbian simply starts with the adjective.

Why the adjective is always neuter

In Moguće je da će porezi porasti (It is possible that taxes will rise), what is possible? The whole clause da će porezi porasti. That clause is the subject of the sentence. A clause has no gender of its own, so Serbian treats it as neuter singular, and the adjective agrees with it: moguće, potrebno, poznato - never moguć, potrebna, poznati. It does not matter what the clause is about: even if it talks about women, or about many people, the adjective stays neuter singular.

• moguć → moguće
• potreban → potrebno
• poznat → poznato
• važan → važno
• jasan → jasno

This is not the adverb, even though it looks like one. In A2 you learned that the neuter adjective also works as an adverb: Ona govori jasno (She speaks clearly). There jasno describes HOW she speaks. In Jasno je da vlada greši (It is clear that the government is wrong), jasno says WHAT the clause is - it is the predicate, joined to its subject by je. Quick test: if the word needs je (or bilo je, nije) next to it and a da-clause follows, it is the impersonal predicate, and it must be the neuter form.

The clause keeps its own subject and tense

Exactly as after mislim da or znam da, the verb after da has its own subject and its own tense: Poznato je da su mladi nezadovoljni (It is well known that young people are dissatisfied), Moguće je da će vlada pasti (It is possible that the government will fall). And je is a clitic, so it stands in second position: Poznato je da..., but Svima je poznato da... (Everyone knows that... - literally 'it is known to everyone'). Negation uses nije: Nije moguće da...

In the past: bilo je

In the past tense the frame becomes bilo je + neuter adjective. Bilo is the neuter participle of biti, and it stays neuter no matter what the clause says, because it agrees with the clause, not with any noun inside it. In the negative: nije bilo.

Do not make bilo agree with a noun in the clause. Bilo je jasno da su ljudi ljuti - not bili su jasno. The people are in the clause; the predicate belongs to the clause as a whole.

The infinitive alternative

When the statement is about people in general and nobody in particular is named, the da-clause can be replaced by a bare infinitive, just as after modal verbs in A2: Važno je glasati (It is important to vote), Potrebno je smanjiti poreze (It is necessary to cut taxes).

As soon as you name WHO should do it, only the da-clause works, because the infinitive has no person: Potrebno je da vlada smanji poreze (The government needs to cut taxes). Never Potrebno je vlada smanjiti.