Nu s-a întâmplat nimic ieri.

S-a is a contraction of se + a.

• se is part of the verb a se întâmpla = to happen
• a is the auxiliary verb used to build the past tense called perfectul compus

So s-a întâmplat means happened or more literally has happened.

In this sentence, Nu s-a întâmplat nimic ieri, the whole verbal part s-a întâmplat is the past form of a se întâmpla.

The hyphen shows that two short grammatical words are being linked together:

• s- = reduced form of se
• a = auxiliary

Romanian often uses hyphens when unstressed pronouns or particles attach to another word. So s-a is the standard written form, not two fully separate words.

No. In this case, se is just part of the normal Romanian verb. It does not usually carry a literal reflexive meaning like it happened itself.

Many Romanian verbs are pronominal or look reflexive even when English does not use a reflexive form. A se întâmpla is simply the standard way to say to happen.

So you should learn it as a full dictionary item:

• a se întâmpla = to happen

Romanian normally uses negative concord, which means multiple negative elements can appear together in the same sentence.

So:

• nu = negates the verb
• nimic = nothing

That is why Nu s-a întâmplat nimic is the normal Romanian structure.

Word-for-word, it may look like Not happened nothing, but the correct English meaning is simply Nothing happened.

This is very common in Romanian:

• Nu văd nimic = I don't see anything / I see nothing
• Nu am pe nimeni = I don't have anyone / I have nobody

It can correspond to either one in English, depending on the sentence.

In a negative Romanian sentence, nimic is often translated naturally as either:

• nothing
• anything

For example:

• Nu s-a întâmplat nimic ieri = Nothing happened yesterday
• You could also think of it as Anything didn't happen yesterday, but that is not natural English, so we translate it as Nothing happened yesterday

So in practice, here nimic is best understood as nothing.

It is the perfectul compus, the Romanian compound past tense.

It is formed with:

• an auxiliary form of a avea
• the past participle

Here:

• a = 3rd person singular auxiliary
• întâmplat = past participle

So:

• se întâmplă = happens / is happening
• s-a întâmplat = happened / has happened

In this sentence, English normally uses the simple past:

• Nothing happened yesterday

The base verb is a se întâmpla.

In s-a întâmplat:

• întâmplat is the past participle
• the full expression is the past tense form of a se întâmpla

So if you look it up in a dictionary, search for a se întâmpla, not just întâmplat.

Romanian does not need a dummy subject like English it in this kind of sentence.

English sometimes requires a grammatical subject even when it has little meaning, but Romanian often does not. The verb form is enough.

Also, in this sentence the real idea being focused on is nimic = nothing. So Romanian naturally says:

• Nu s-a întâmplat nimic

There is no need for an extra word meaning it.

Yes, Romanian word order is fairly flexible. Ieri means yesterday, and it can appear in different positions.

All of these are natural:

• Nu s-a întâmplat nimic ieri
• Ieri nu s-a întâmplat nimic

The version with ieri at the end is very natural and neutral. Putting ieri first gives a little more emphasis to the time:

• Yesterday, nothing happened

The word întâmplat contains Romanian diacritics that matter for pronunciation.

• î represents a central vowel sound that English does not really have
• â represents the same sound as î inside a word

So in întâmplat, both î and â sound the same.

A rough approximation for English speakers is something like:

• in-tuhm-PLAT

But that is only approximate. The stress is on the last syllable:

• în-tâm-PLAT

Also remember:

• ă is a short neutral vowel, like a schwa sound in English sofa
• â / î is a different Romanian vowel, not the same as ă

Yes, but the meaning or style changes.

For example:

• Nu s-a întâmplat nimic ieri = Nothing happened yesterday
• Ieri nu s-a întâmplat nimic = same meaning, different emphasis

If you remove nimic, you get something incomplete or a different meaning. Nimic is the word that tells us nothing happened.

So for the exact meaning Nothing happened yesterday, nimic is necessary.