Ha caigut aigua sobre la taula.

Ha caigut is the present perfect of caure, meaning to fall.

It is made with:

• ha = has, from the auxiliary verb haver
• caigut = fallen, the past participle of caure

So ha caigut literally means has fallen.

In Catalan, it is very common for the subject to come after the verb with verbs like caure, especially when the subject is:

• indefinite
• new information
• a thing appearing or happening unexpectedly

So Ha caigut aigua is a very natural word order.

If you put the subject first, Aigua ha caigut, it sounds marked and much less natural in normal speech. If the water is specific, then L’aigua ha caigut sobre la taula is more normal.

Here aigua means some water, not the water.

Catalan often uses a bare noun with mass nouns like:

• aigua = water
• vi = wine
• llet = milk

So Ha caigut aigua means Some water has fallen or Water has fallen.

If you said Ha caigut l’aigua, that would usually mean a specific water already known from the context, such as the water from the glass.

Grammatically, ha caigut is has fallen.

But in English, depending on context, you might translate it as either:

• Water has fallen on the table
• Water fell on the table

Catalan often keeps the compound form when the result is still relevant now, for example if the table is still wet.

If you wanted a more straightforward past event, Catalan often uses va caure:

• Va caure aigua sobre la taula = Water fell on the table

Because with the auxiliary haver, the past participle normally does not agree with the subject.

So you say:

• Ha caigut aigua
• Han caigut gotes

not:

• Ha caiguda aigua

Agreement appears when the participle is used like an adjective, not in the compound tense. For example:

• les fulles caigudes = the fallen leaves

There, caigudes agrees with fulles.

Aigua is feminine.

You can see that in phrases like:

• aigua freda = cold water
• molta aigua = a lot of water
• l’aigua = the water

So even though the word form may not make it obvious at first, treat aigua as a feminine noun.

Sobre la taula means on the table or onto the table.

That works well here because the idea is that the water ended up on the table’s surface.

A la taula usually means:

• at the table
• to the table

So it normally does not mean on the table.

Another possible expression is:

• damunt de la taula = on top of the table

That is also natural, though sobre la taula is very common and compact.

Yes, caure is perfectly natural with water.

It can be used when water:

• drips
• falls from somewhere
• lands somewhere accidentally

So Ha caigut aigua sobre la taula is a normal way to say that water has ended up falling onto the table.

If you want to emphasize spilling, Catalan can use a more specific verb, for example:

• S’ha vessat aigua sobre la taula = Water has spilled onto the table

The difference is:

• caure = fall, a broad idea
• vessar-se = spill, more specific

Yes, but it means something slightly different.

• Ha caigut aigua sobre la taula = Some water / water has fallen on the table
• L’aigua ha caigut sobre la taula = The water has fallen on the table

So the version with l’aigua refers to specific water already identified in the conversation or context.

The sentence you were given sounds more like introducing the event itself: there is water on the table, and that is new information.