Avus dicit mores hominum paulatim mutari.

Because after a verb like dicit (he says), Latin often uses indirect statement.

Instead of saying:

• Avus dicit quod mores hominum paulatim mutantur

Latin much more naturally says:

• Avus dicit mores hominum paulatim mutari

This is the accusative + infinitive construction:

• dicit = he says
• mores = the subject of the reported statement, put in the accusative
• mutari = the infinitive

So Latin expresses “Grandfather says that …” by using an accusative noun plus an infinitive, rather than a separate that-clause.

Because mores has the same form in both the nominative plural and the accusative plural.

For this noun:

• nominative singular: mos
• accusative singular: morem
• nominative plural: mores
• accusative plural: mores

So in this sentence, mores is functioning as the accusative subject of mutari, even though its form looks identical to the nominative plural.

This is very common in Latin: sometimes you have to identify the case from the construction, not just the ending.

Hominum is the genitive plural of homo, meaning of people or of men/human beings.

So:

• mores hominum = the customs/morals/character of people

The genitive here shows possession or association. It tells you whose mores are being talked about.

It can cover several related ideas:

• customs
• habits
• moral values
• character
• social behavior

Latin mos, mores is broader than the English word morals. Depending on context, mores hominum might mean:

• people’s customs
• human behavior
• the morals of people
• the character of mankind

So this is a word worth learning as a range of meanings, not just a single English equivalent.

Mutari is the present passive infinitive of mutare (to change).

Forms:

• mutare = to change
• mutari = to be changed

So grammatically, the sentence says that the mores of people are being changed or change in a passive sense.

In English, depending on context, we may translate more naturally in different ways, but the Latin form itself is definitely passive.

Sometimes, yes, depending on what meaning has been given to the learner.

Latin may use a passive form where English prefers something a bit more flexible, especially with broad ideas like customs or morals. But grammatically, you should still recognize:

• mutari = to be changed

So even if a smoother English translation is chosen, the form you are parsing is passive infinitive.

It is the present passive infinitive.

That means it expresses action happening at the same time as the main verb, from the point of view of the main verb:

• Avus dicit ... mutari = Grandfather says ... are being changed / change

In indirect statement:

• present infinitive = action simultaneous with the main verb
• perfect infinitive = action earlier than the main verb
• future infinitive = action later than the main verb

So mutari suggests something going on at the time he says it.

Paulatim means gradually, little by little, or by degrees.

Here it modifies mutari:

• mores hominum paulatim mutari
• the mores of people gradually to be changed
• more naturally: that people’s customs/morals are gradually changing / being changed

So paulatim describes how the change happens.

Yes. Latin word order is flexible because the endings show the grammatical relationships.

This sentence is arranged as:

• Avus = subject
• dicit = main verb
• mores hominum = content of what is said
• paulatim mutari = infinitive phrase

A different order could still be grammatical, for example:

• Avus mores hominum paulatim mutari dicit
• Mores hominum avus paulatim mutari dicit

The chosen order is fairly natural and easy to follow. Often Latin puts the main verb of speaking early, then gives the indirect statement after it.

Because avus is in the nominative singular, and dicit is third person singular.

So:

• avus = grandfather
• dicit = he says

They match as subject and verb.

Meanwhile, mores belongs not to dicit directly as its object in the ordinary sense, but to the indirect statement after dicit.

Indirect speech.

Direct speech would be something like:

• Avus dicit: “Mores hominum paulatim mutantur.”
• Grandfather says: “People’s customs are gradually changing.”

But in your sentence, Latin has converted that idea into indirect statement:

• Avus dicit mores hominum paulatim mutari

That is one of the most important constructions in Latin, so this sentence is a good example to study.

Here are the basic dictionary forms:

• avus, -i = grandfather
• dico, dicere, dixi, dictum = say, tell
• mos, moris = custom, habit, moral practice, character
• homo, hominis = human being, person, man
• paulatim = gradually
• muto, mutare, mutavi, mutatum = change

And in this sentence:

• Avus = nominative singular
• dicit = 3rd person singular present active
• mores = accusative plural in indirect statement
• hominum = genitive plural
• paulatim = adverb
• mutari = present passive infinitive

A helpful way to divide it is:

• Avus dicit = the main clause
• mores hominum paulatim mutari = the indirect statement

Inside the indirect statement:

• mores = accusative subject
• hominum = dependent genitive
• paulatim = adverb
• mutari = infinitive

So the pattern is:

[subject] + [verb of saying] + [accusative subject] + [infinitive]

That is a core Latin pattern worth memorizing.