Rubor labri iam minor est, et mater dicit labrum mox sanescere posse.

Because labri is the genitive singular of labrum. It depends on rubor and shows possession or relationship: rubor labri = the redness of the lip.

A native English speaker often expects something more like an adjective, but Latin very commonly uses the genitive in this kind of phrase.

They are two different case forms of the same noun, labrum.

• labri = genitive singular, used with rubor
• labrum = accusative singular, used as the subject of the indirect statement after dicit

So the sentence uses the same noun twice, but each time with a different grammatical job.

Because minor is the comparative adjective form, and it agrees with rubor.

• rubor is masculine singular nominative
• so the matching comparative adjective is minor

Minus can be:

• the neuter form of the comparative adjective, or
• an adverb meaning less

Here Latin needs an adjective describing rubor, so minor is correct.

Minor est means is smaller / less. In this sentence, minor is a predicate adjective with est.

So the structure is:

• rubor = subject
• minor = predicate adjective
• est = linking verb

It works like The redness is less.

Iam often means now or already, depending on context. Here it suggests a change has already begun or is noticeable by now.

So iam minor est gives the sense that the redness is now less or already less.

After verbs of saying, thinking, knowing, and perceiving, Latin very often uses an indirect statement, also called the accusative-and-infinitive construction.

So instead of saying something literally like mother says that the lip can heal soon, Latin says:

• mater dicit
• labrum = accusative subject of the reported statement
• sanescere posse = infinitive phrase

This is one of the most important Latin sentence patterns to learn.

Because in an indirect statement, the logical subject is put in the accusative, not the nominative.

So in a direct statement, you would have something like:

• labrum mox sanescere potest

But after dicit, Latin changes the subject of the reported statement to accusative:

• mater dicit labrum mox sanescere posse

That is why labrum is accusative even though it is the thing doing the healing.

Because posse normally takes another infinitive with it.

• posse = to be able
• sanescere = to heal / get better

So sanescere posse means to be able to heal or to be able to get better.

In the indirect statement after dicit, both verbs appear in the infinitive:

• posse is the main verb of the reported statement
• sanescere depends on posse

This is a very good vocabulary question.

• sanare usually means to heal or cure something, often as a transitive verb
• sanescere means to begin to become healthy, to recover, or to heal up

So sanescere is especially suitable when something is getting better on its own. A lip can sanescere. A doctor might sanare a wound or patient.

Mox means soon.

It modifies the verbal idea sanescere posse, so the sense is that the lip will be able to heal soon.

Latin word order is flexible, so mox can stand near the infinitives without causing confusion.

It may feel unusual from an English point of view, but it is perfectly normal Latin.

The sentence is organized by endings more than by fixed word order:

• Rubor labri iam minor est
• et mater dicit labrum mox sanescere posse

A few things to notice:

• rubor comes first, giving prominence to the topic
• labri follows to define what kind of redness
• minor est comes at the end of the clause, which is very natural in Latin
• in the second clause, labrum appears early so you know the subject of the indirect statement quickly
• posse comes last, which is also very typical Latin style

Not always. Rubor can mean redness, blushing, or even shame-colored redness, depending on context.

In this sentence, because it is connected with labrum and healing, it clearly refers to physical redness rather than emotional blushing.