Moveré la maceta colgante sin que caiga la composta.

Moveré is the first-person singular simple future of mover, meaning I will move.

So:

• mover = to move
• moveré = I will move

The simple future is formed by adding endings to the infinitive:

• moveré = I will move
• moverás = you will move
• moverá = he/she/it will move

So the sentence begins with Moveré... = I will move...

In Spanish, adjectives usually come after the noun, especially when they are just describing a normal quality.

So:

• maceta = flowerpot / planter
• colgante = hanging

Together, la maceta colgante means the hanging planter or the hanging flowerpot.

Putting colgante after the noun is the normal word order here.
If you moved the adjective before the noun, it would sound unusual or stylistically marked.

Maceta is a flowerpot, plant pot, or planter.

Colgante means hanging or that hangs.

So maceta colgante is a hanging planter or hanging pot—a pot suspended from above, not one sitting on the ground.

Spanish uses sin que when it is followed by a whole clause with a conjugated verb.

Here, the second part is:

• que caiga la composta = that the compost falls

So you need:

• sin que caiga la composta = without the compost falling

Compare:

• sin caer = without falling
• sin que caiga la composta = without the compost falling

A useful rule:

• sin + infinitive → when there is no new conjugated verb
• sin que + subjunctive → when a new clause follows

Because after sin que, Spanish normally uses the subjunctive.

So:

• cae = present indicative
• caiga = present subjunctive

The sentence is not stating that the compost actually falls. It is expressing something to avoid:

• without the compost falling

That kind of idea—something uncertain, prevented, intended, or not asserted—commonly triggers the subjunctive.

So:

• sin que caiga la composta = without the compost falling

Caiga comes from the verb caer (to fall) in the present subjunctive.

Present subjunctive forms of caer:

• yo caiga
• tú caigas
• él/ella/usted caiga
• nosotros caigamos
• ellos/ustedes caigan

In this sentence, the subject is la composta, which is third-person singular, so the form is caiga.

Even though yo caiga and ella caiga look the same, the subject tells you which meaning is intended. Here it is clearly:

• la composta caiga = the compost falls

Because caer is an intransitive verb here: something falls.

So the thing doing the falling is the subject:

• la composta cae = the compost falls

In the sentence:

• sin que caiga la composta

the word order is a little flexible, but la composta is still the subject of caiga.

It is not the object. Spanish often places the subject after the verb, especially in subordinate clauses.

Composta means compost.

In much of Latin America, composta is a normal word for compost, especially in gardening or ecological contexts. Depending on the country or speaker, you may also hear:

• compost
• abono (fertilizer / compost, depending on context)

So in this sentence, la composta refers to the compost or organic material inside the planter.

Spanish uses definite articles (el, la, los, las) more often than English does.

Here:

• la maceta colgante = the hanging planter
• la composta = the compost

The article suggests we are talking about specific things in context—the planter and its compost.

English might sometimes drop the article in a more general phrase, but Spanish often keeps it.

Not naturally in this exact form, because the clause after sin que has its own subject:

• la composta is the thing that might fall

If the subject stayed the same, Spanish would often use an infinitive. For example:

• Moveré la maceta colgante sin tirarla.
  = I will move the hanging planter without dropping it.

But in your sentence, the idea is specifically:

• I will move the planter without the compost falling

Since that second action has its own subject, sin que + subjunctive is the normal structure.

Yes, it is grammatical and understandable.

It sounds careful and slightly formal or deliberate, like someone explaining what they will do. In everyday speech, some speakers might also say things such as:

• Voy a mover la maceta colgante sin que se caiga la composta.
• Voy a mover la maceta colgante con cuidado para que no se caiga la composta.

Those alternatives may sound a bit more conversational, but your original sentence is perfectly correct.

Both caiga and se caiga can appear with verbs of falling, depending on nuance and regional preference.

• caer = to fall
• caerse = to fall / to fall down

In many everyday situations, Spanish speakers often use caerse when talking about something accidentally falling:

• Que no se caiga la composta

That can sound especially natural in conversation.

Your sentence uses caiga, which is still correct. It simply uses the non-reflexive verb caer.

Yes. Both are correct:

• Moveré = I will move
• Voy a mover = I’m going to move

In many varieties of spoken Spanish, ir a + infinitive is very common in everyday conversation, while the simple future can sound a bit more formal, more written, or more deliberate.

So:

• Moveré la maceta colgante... = correct
• Voy a mover la maceta colgante... = also correct, often more conversational