Stella vaga per caelum movetur.

Because vaga describes stella, and stella is a feminine singular noun.

In Latin, adjectives must agree with the nouns they describe in:

• gender
• number
• case

So:

• stella = nominative singular feminine
• vaga = nominative singular feminine

That agreement shows that vaga belongs with stella and means wandering, roving, or straying.

Stella is nominative singular, which is the case normally used for the subject of a sentence.

We know it is the subject because:

• its form fits the nominative singular
• vaga agrees with it in nominative singular feminine
• the verb movetur is third person singular, matching a singular subject

So stella vaga is the subject phrase: the wandering star or a wandering star.

Because it comes after the preposition per, and per takes the accusative case.

So:

• per = through, across
• caelum = accusative singular of caelum

Together, per caelum means through the sky.

This is a very common pattern in Latin: certain prepositions require a specific case, and per almost always takes the accusative.

This is probably one of the first things an English speaker notices.

Movetur is formally the present passive form of movet:

• movet = he/she/it moves or he/she/it moves something
• movetur = he/she/it is moved

But in Latin, passive forms of some verbs can sometimes be used in a way that is closer to moves, is in motion, or moves along, especially when the context clearly does not emphasize an outside agent.

So in this sentence, movetur is understood more naturally as something like:

• moves
• is moving
• is carried along

A learner might first expect movet, but Latin can use movetur in this kind of sense.

Yes. By form alone, movetur does literally mean is moved.

So if you only looked at the verb form by itself, you might expect a passive translation. But Latin often depends on context. In this sentence, with stella vaga and per caelum, the idea is naturally that the star is moving across the sky.

So the form is passive, but the overall sense is closer to moves through the sky.

Because Latin word order is much freer than English word order.

In English, we usually say the wandering star, with the adjective before the noun. In Latin, an adjective can come:

• before the noun
• after the noun
• separated from the noun

As long as the forms agree, the relationship is clear.

So stella vaga is perfectly normal Latin for wandering star.

Yes. Latin word order is flexible, so several arrangements would still make grammatical sense, such as:

• Vaga stella per caelum movetur
• Per caelum stella vaga movetur
• Stella per caelum vaga movetur

The basic meaning would stay much the same, though the emphasis might shift slightly.

For example:

• putting per caelum earlier can emphasize through the sky
• putting vaga earlier can emphasize the idea of wandering

Because Classical Latin has no articles.

So stella can mean:

• a star
• the star

You decide which is better from the context.

The same is true for stella vaga:

• a wandering star
• the wandering star

English requires an article, but Latin usually does not.

Not only that. Vagus, vaga, vagum has a range of related meanings, including:

• wandering
• roving
• straying
• unfixed
• rambling

In this sentence, wandering is a very natural choice, especially with a star moving through the sky.

Per gives the idea of movement through or across something.

So:

• movetur by itself = moves / is moved
• per caelum movetur = moves through the sky

Without per, the sentence would feel less specific about the path of motion. Per tells you the movement goes through the space of the sky.

It can mean both, depending on context.

Caelum may be translated as:

• sky
• heaven
• the heavens

In this sentence, sky is usually the most natural translation, because the image is of a star moving across the visible sky.

Because of agreement.

• stella is feminine singular
• vaga is feminine singular
• caelum is neuter singular

If vaga described caelum, it would need to be vagum, not vaga.

So the grammar clearly tells you that vaga goes with stella.

The dictionary forms are:

• stella — stella, stellae — star
• vaga — from vagus, vaga, vagum — wandering, roving
• per — preposition meaning through, across
• caelum — caelum, caeli — sky, heaven
• movetur — from moveo, movere, movi, motum — move

Looking up words by their dictionary form is important, because the actual form in the sentence may be changed for case, number, gender, tense, voice, or person.

Here is the breakdown:

• stella — noun
• vaga — adjective
• per — preposition
• caelum — noun
• movetur — verb

So the structure is basically:

noun + adjective + prepositional phrase + verb

That gives: stella vaga = subject phrase
per caelum = prepositional phrase
movetur = verb