Astrologus astra contemplatur.

Astrologus is nominative singular. Its job is to be the subject of the sentence: the person who is doing the action.

It comes from the noun astrologus, astrologi (masculine), a second-declension noun.

So:

• astrologus = nominative singular
• subject = the one who does the verb

Because astra is a neuter plural form.

It comes from astrum, astri (neuter), meaning star. In the second declension, neuter nouns have these important patterns:

• singular nominative/accusative: -um
• plural nominative/accusative: -a

So:

• astrum = one star
• astra = stars

This is very common with neuter nouns in Latin.

Here astra is accusative plural, because it is the direct object of the verb: it receives the action of contemplatur.

So the sentence has:

• astrologus = subject
• astra = direct object
• contemplatur = verb

A useful thing to remember is that for many neuter nouns, the nominative plural and accusative plural look the same. So astra could be either form in isolation, but in this sentence it is understood as accusative plural.

Contemplatur is:

• third person singular
• present tense
• indicative mood
• from the verb contemplor, contemplari, contemplatus sum

So it means he/she contemplates, looks at, or observes, depending on context.

The third person singular matches the singular subject astrologus.

Because contemplor is a deponent verb.

Deponent verbs are special Latin verbs that:

• use passive-looking forms
• but have active meanings

So contemplatur looks as if it might mean something passive, but it actually means he/she contemplates, not he/she is contemplated.

This is one of the most important things for Latin learners to get used to.

In appearance, yes. In function, no.

For a regular verb, a form ending in -tur is usually third person singular passive. But with a deponent verb like contemplor, that same kind of form has an active meaning.

So:

• regular passive-looking form: often passive in meaning
• deponent passive-looking form: active in meaning

That is why vocabulary is important: when you learn contemplor, you should learn that it is deponent.

Because Latin has no articles. It does not have separate words that exactly match English the, a, or an.

So astrologus can mean:

• the astrologer
• an astrologer
• sometimes just astrologer, depending on context

And astra can mean:

• the stars
• stars

English must choose an article; Latin usually leaves that to context.

Latin often places the verb at or near the end of the sentence, especially in simple prose. So subject + object + verb is a very common pattern:

• Astrologus = subject
• astra = object
• contemplatur = verb

That said, Latin word order is more flexible than English word order, because the endings show the grammatical roles.

So this sentence could be rearranged, for example:

• Astra astrologus contemplatur
• Contemplatur astrologus astra

These can still mean the same basic thing, though the emphasis may change.

Mainly because of the case endings and the verb.

• Astrologus is clearly nominative singular
• contemplatur is singular
• astra can be nominative plural or accusative plural in form, but here it fits as the object

So the grammar points us toward:

• astrologus as subject
• astra as object

This is a good example of how Latin relies on endings rather than strict word order.

The dictionary forms are:

• astrologus, astrologi — masculine noun
• astrum, astri — neuter noun
• contemplor, contemplari, contemplatus sum — deponent verb

For nouns, Latin dictionaries usually give:

• nominative singular
• genitive singular
• gender

For verbs, dictionaries usually give principal parts. With a deponent verb, the forms look different from those of a regular active verb, so it is worth memorizing them carefully.

Yes. Latin often omits the subject pronoun or even the subject noun if the context is clear.

Since contemplatur already means he/she contemplates, a Latin sentence could simply say:

• Astra contemplatur

That would mean something like He/She contemplates the stars, if the subject were already understood from context.

In the full sentence, astrologus is included for clarity or emphasis.

A common restored Classical pronunciation would be roughly:

as-TRO-lo-gus AS-tra kon-tem-PLA-tur

A few details:

• g is always hard, as in go
• c is always hard, as in cat
• a is pronounced like a in father
• astr- in astra has a clear str cluster

If you want a more detailed version, it is often given approximately as:

as-TRO-lo-gus AS-tra kon-tem-PLA-tur

with the stress on:

• -tro- in astrologus
• as- in astra
• pla- in contemplatur