Il condomino si astiene: la decisione non è unanime.

Condomino is a person who owns or co-owns an apartment/unit in a condominio and takes part in condominium matters, such as meetings and votes.

So in this kind of context, il condomino usually means the unit owner / co-owner / member of the condominium association, not just any person living in the building.

A useful distinction is:

• condominio = condominium / apartment building under shared ownership
• condomino = condominium owner / co-owner / member of that condominium

Because the verb is astenersi, a pronominal verb, meaning to abstain or to refrain.

Its infinitive is:

• astenersi = to abstain

So in the present tense:

• io mi astengo
• tu ti astieni
• lui/lei si astiene
• noi ci asteniamo
• voi vi astenete
• loro si astengono

The si is not optional here; it is part of the verb.

It is the present indicative, third person singular:

• si astiene = he/she abstains or is abstaining

In this sentence, it most likely describes what happens during a vote or decision-making process.

No. Si astiene means the person abstains, usually from voting.

So the person is still part of the process, but does not vote for or against.

That is different from being absent:

• è assente = is absent
• si astiene = abstains

Italian often leaves that unstated when the context is obvious.

Here, the sentence strongly suggests a voting context, so si astiene is understood as:

• abstains from voting
• abstains in the vote

If you wanted to make it explicit, you could say something like:

• Il condomino si astiene dal voto = The condominium owner abstains from the vote

But in short notices or formal summaries, the shorter version is very common.

The colon links the two ideas very tightly. It works like:

• The condominium owner abstains; therefore / as a result, the decision is not unanimous
• or The condominium owner abstains: this means the decision is not unanimous

So the second part explains the consequence of the first part.

English might use a colon, semicolon, or even a full stop depending on style.

Because unanime is an adjective that has the same form for both masculine and feminine singular.

So:

• un voto unanime
• una decisione unanime

Both use unanime.

In the plural, it becomes:

• unanimi

Examples:

• Le decisioni non sono unanimi
• I pareri sono unanimi

Because è with an accent is the verb is (from essere).

Compare:

• è = is
• e = and

So:

• la decisione non è unanime = the decision is not unanimous
• la decisione e il voto would mean the decision and the vote

The accent is important because it distinguishes two different words.

They are the definite articles:

• il condomino = the condominium owner
• la decisione = the decision

In context, this usually refers to a specific owner and a specific decision already known in the situation, such as in meeting minutes or a report.

Italian uses definite articles very naturally in cases where English sometimes does too, and sometimes does not.

Usually no, or at least not safely.

A tenant is someone who rents a place.
A condomino is usually an owner/co-owner or an official member of the condominium body.

So tenant may be wrong unless the broader context clearly uses the word more loosely, which is less typical.

Better options are:

• condominium owner
• co-owner
• unit owner
• sometimes resident owner, depending on context

Yes. Italian has several ways to express the idea that a decision was not unanimous. For example:

• La decisione non è unanime
• La decisione non è stata presa all’unanimità
• La decisione non è passata all’unanimità

These are similar, but not always identical in tone:

• non è unanime = the decision is not unanimous
• non è stata presa all’unanimità = the decision was not taken unanimously
• non è passata all’unanimità = the decision did not pass unanimously

The original sentence is short and formal, which fits meeting or administrative language well.

Not if you want to emphasize a completed past event. Then you would normally use a past tense, for example:

• Il condomino si è astenuto = The condominium owner abstained / has abstained

That is the passato prossimo of astenersi.

So:

• si astiene = abstains / is abstaining
• si è astenuto = abstained / has abstained

In your sentence, the present tense can sound like a summary style, especially in notices, reports, or captions.