Dolor brevis non diu manet.

The subject is dolor brevis and the finite verb is manet.

• dolor = the noun
• brevis = the adjective modifying dolor
• manet = remains / stays / lasts
• non diu modifies manet, telling you for how long

So the basic structure is:

[subject] dolor brevis + [adverb] non diu + [verb] manet

Latin does not have articles like English a, an, and the.

So dolor can mean:

• pain
• a pain
• the pain

Context tells you which is most natural in translation. This is very normal in Latin.

dolor is nominative singular.

It is nominative because it is the subject of manet. In other words, dolor is the thing that remains / lasts.

Its dictionary entry is usually given as dolor, doloris, so here you are seeing the nominative singular form.

Because brevis is a third-declension adjective.

For this type of adjective:

• masculine nominative singular = brevis
• feminine nominative singular = brevis
• neuter nominative singular = breve

So even though dolor is masculine, brevis is exactly the correct form. It agrees with dolor in:

• gender: masculine
• number: singular
• case: nominative

English speakers often expect a masculine ending like -us, but that is only true for many first/second-declension adjectives, not for all adjectives.

Here it is most naturally a noun + adjective phrase: brief pain.

So brevis is modifying dolor, not acting as a separate predicate with an understood est.

That matters because the sentence already has its main verb, manet. The structure is not really pain is brief and does not remain long; rather, it is brief pain does not remain long.

diu is an adverb meaning for a long time or long in the sense of duration.

So:

• diu = for a long time
• non diu = not for a long time, more naturally not long

This is different from using an adjective like brevis.
An adjective describes a noun; an adverb describes a verb.

So:

• brevis describes dolor
• non diu describes manet

manet is:

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

It comes from manere, meaning to remain, to stay, or sometimes to last.

Because it is third person singular, it matches the singular subject dolor.

Latin usually does not need an expressed subject pronoun unless it is being emphasized.

The ending -et in manet already tells you the verb is third person singular, so Latin does not need to add it.

And in this sentence the subject is already named explicitly as dolor brevis, so nothing is missing.

Yes. In Latin, adjectives often come after the nouns they modify.

So dolor brevis is perfectly normal. Latin word order is much freer than English word order because the endings show grammatical relationships.

English strongly prefers brief pain.
Latin can say dolor brevis without causing confusion.

They are similar in idea, but they are not doing exactly the same job.

• brevis describes the pain itself as brief
• non diu manet says that it does not last long

So there is some overlap, but it is not bad Latin. It creates a kind of reinforcement or emphasis: the pain is short, and it does not continue for long.

Languages often do this for style.

Yes, to a large extent.

Because the forms show the grammar, Latin can move words around more freely than English. For example, forms like these would still be understandable:

• Non diu dolor brevis manet
• Dolor non diu brevis manet
• Manet non diu dolor brevis

However, not all orders sound equally natural, and changing the order can change the emphasis. The given order keeps dolor brevis together and places non diu right before manet, which is clear and straightforward.

No. dolor can refer to:

• physical pain
• grief
• sorrow
• emotional distress

Which meaning is best depends on context. In a short sentence like this, it can feel quite general unless a larger context makes it more specific.