Они спорили о собственности.

Спорили is the past tense plural form of the verb спорить.

• infinitive: спорить = to argue / to dispute
• past masculine singular: спорил
• past feminine singular: спорила
• past neuter singular: спорило
• past plural: спорили

It agrees with они because они is plural.

Also, спорить is imperfective, so спорили usually suggests an ongoing process, repeated arguing, or simply describes the fact that they were engaged in an argument.

Спорить is a very common verb meaning to argue, dispute, debate.

It is often used:

• with с кем = to argue with someone
  • спорить с братом = to argue with one’s brother
• with о чём = to argue about something
  • спорить о политике = to argue about politics

So in Они спорили о собственности, the pattern is very standard:

• они = they
• спорили = were arguing / argued
• о собственности = about property / ownership

After the preposition о in the meaning about, Russian normally uses the prepositional case.

So:

• dictionary form: собственность
• prepositional: о собственности

This is why the ending changes from -ь to -и.

A useful pattern is:

• говорить о... = to talk about...
• думать о... = to think about...
• спорить о... = to argue about...

So о собственности literally means about property / about ownership.

It can suggest either, depending on context.

Собственность often means:

• property in a legal or economic sense
• ownership
• possession in formal contexts

So Они спорили о собственности could mean:

• they were arguing about property
• they were arguing about ownership
• they were disputing who owned something

Without more context, Russian leaves that somewhat open.

Russian often uses a singular abstract noun where English might also use a singular abstract noun.

Here собственность refers to the general concept of property / ownership rather than a list of separate items.

So the singular sounds natural if the discussion is about:

• the issue of ownership
• property rights
• a particular piece of property as a legal matter

If you wanted to emphasize multiple properties or possessions, Russian might use different wording, depending on context.

Yes, in natural English that may be a very good translation.

Russian спорить о чём-то literally corresponds to argue about something, but in context it can also be understood as:

• argue over property
• have a dispute over ownership

English often prefers over when the argument concerns something contested. Russian uses о very naturally here.

It would mean something slightly different.

• спорить о собственности = to argue about property / ownership
• спорить из-за собственности = to argue because of property / over property as the cause of the argument

So:

• о focuses on the topic
• из-за focuses on the cause

In many contexts both are possible, but they are not exactly the same.

Yes, often it can.

Russian past-tense verbs show number, and in the singular they also show gender. So спорили already tells you the subject is plural.

That means Спорили о собственности can be possible in context, especially in narration, if it is already clear who they are.

However, Они спорили о собственности is perfectly normal and may be used:

• for clarity
• for emphasis
• at the start of a sentence or story

The stress is:

• онИ
• спОрили
• о сОбственности

So the sentence is pronounced approximately as:

анИ спОрили а сОбственности

A few notes:

• о is often pronounced more like a in unstressed position
• the stress in собственность stays on the first syllable: сОбственность
• in the prepositional form собственности, the stress stays there too: сОбственности

Спорить is imperfective.

The imperfective is used because the sentence presents the argument as a process or ongoing event:

• they were arguing about property
• they argued about property

Russian often uses the imperfective in past tense when simply describing what was happening.

A perfective partner such as поспорить usually refers more to a completed instance of arguing:

• Они поспорили о собственности = they had an argument / they argued once about property

So спорили sounds more neutral and descriptive.

Yes, you could.

Russian word order is more flexible than English. The basic sentence:

• Они спорили о собственности

is the most neutral order.

But you can change the order for emphasis:

• О собственности они спорили = It was about property that they were arguing
• Спорили они о собственности = slightly marked, maybe contrasting with some other action

The meaning stays basically the same, but the emphasis changes.

Yes, собственность is feminine.

A good clue is that many nouns ending in -ость are feminine:

• новость = news
• скорость = speed
• возможность = possibility
• собственность = property / ownership

In the dictionary form, it ends in a soft sign -ь, and nouns of this type are very often feminine.

That is why its prepositional form is:

• о собственности

Here are a few useful parallels:

• Они спорили о деньгах. = They were arguing about money.
• Мы говорили о работе. = We were talking about work.
• Она думала о будущем. = She was thinking about the future.
• Они спорили о правах собственности. = They were arguing about property rights.

These all use the pattern:

verb + о + prepositional case