Pulmo aerem recipit.

Pulmo is nominative singular, which is the case normally used for the subject of a sentence in Latin.

So in Pulmo aerem recipit, pulmo is the thing doing the action: the lung receives/takes in the air.

A learner might expect a masculine subject to end in -us, but pulmo is a third-declension noun, so its nominative singular form is simply pulmo.

Because aerem is the direct object of the verb, so it must be in the accusative singular.

The dictionary form is aer, but Latin changes noun endings depending on their role in the sentence:

• aer = nominative singular
• aerem = accusative singular

So aerem means air as the thing being received or taken in.

Recipit is:

• third person singular
• present tense
• active voice
• indicative mood

It comes from the verb recipio, recipere, meaning receive, take back, or in many contexts take in.

Here, recipit means he/she/it receives or takes in. Since the subject is pulmo = lung, the natural English meaning is the lung takes in air.

We know because of the endings, not mainly because of the word order.

• pulmo is nominative → subject
• aerem is accusative → direct object
• recipit is singular → it matches the singular subject pulmo

So even if the words were rearranged, the endings would still show that the lung is doing the action and the air is what is being taken in.

Latin usually does not use articles like English the or a/an.

So pulmo can mean:

• a lung
• the lung
• sometimes just lung in a general sense

And aerem can mean air without needing an article at all.

English has to choose an article, but Latin often leaves that to context.

Not as much as in English.

Latin word order is flexible because the grammatical endings tell you each word’s role. So these could all mean basically the same thing:

• Pulmo aerem recipit
• Aerem pulmo recipit
• Recipit pulmo aerem

That said, subject + object + verb is a very normal Latin order, especially in simple teaching sentences.

Yes. The basic meaning of recipit is receives or takes back, depending on context.

But verbs often sound a little different in natural English depending on the situation. With air, English usually says:

• takes in air
• inhales air

more naturally than receives air.

So receives is closer to the Latin verb itself, but takes in is often the better English translation.

A good learner’s set would be:

• pulmo, pulmonis = lung
• aer, aeris = air
• recipio, recipere, recepi, receptum = receive, take back, take in

For nouns, Latin dictionaries usually give the nominative and genitive singular, because that tells you how the noun declines.

For verbs, dictionaries usually give the main parts, which help you form other tenses and stems.

• pulmo, pulmonis is a third-declension noun
• aer, aeris is also a third-declension noun
• recipio, recipere is a third-conjugation -io verb

This matters because it tells you what endings the words will use in other forms.

For example:

• pulmo → pulmonis, pulmonem, pulmones
• aer → aeris, aerem
• recipio → recipis, recipit, recipiunt

You would change both the subject noun and the verb:

• pulmo → pulmones = lungs
• recipit → recipiunt = receive / take in

So:

Pulmones aerem recipiunt.

This means the lungs take in air.

Notice that aerem can stay singular in Latin, just as air usually stays singular in English because it is a mass noun.