Qui in suburbio manent, interdum ruri quietiorem vitam quaerunt.

Because qui is a relative pronoun, and in this sentence it is being used substantively: it does not refer back to an expressed noun such as homines or ei. Latin often leaves that noun understood.

So qui in suburbio manent literally means something like the ones who live in the suburb/suburbs or those who live in the suburbs.

Grammatically, qui is:

• nominative plural masculine
• the subject of manent

You can think of an understood noun behind it, such as homines: [homines] qui in suburbio manent.

Qui is nominative plural masculine.

You can tell because:

• it is the subject of manent = live / remain
• the verb manent is 3rd person plural, so its subject must be plural
• the masculine plural nominative form of the relative pronoun is qui

Its basic form is:

• masculine singular: qui
• masculine plural: qui
• feminine singular: quae
• feminine plural: quae
• neuter singular: quod
• neuter plural: quae

Here the sense is people who, so masculine plural is the normal default.

Because in with a place can take either:

• ablative for location = in / on
• accusative for motion into = into

Here there is no movement; the people live there. So Latin uses the ablative:

• in suburbio = in the suburb/suburbs
• in suburbium would mean into the suburb/suburbs

So suburbio is ablative singular of suburbium.

Suburbium refers to the area outside or around a city, so in suburbio can be understood as:

• in the suburb
• in the suburbs
• on the outskirts

Depending on context, English often prefers the suburbs even though Latin has a singular form here.

Manent is:

• 3rd person plural
• present tense
• active voice
• indicative mood

It comes from maneo, manere, meaning remain, stay, or sometimes live depending on context.

So here:

• qui ... manent = those who live ...

Latin often uses verbs like maneo in ways that overlap with English live, stay, or remain.

Interdum is an adverb meaning:

• sometimes
• from time to time
• occasionally

It modifies the main verb quaerunt.

So the structure is:

• Qui in suburbio manent = the subject
• interdum = sometimes
• ruri quietiorem vitam quaerunt = seek a quieter life in the country

Because ruri is a special form called the locative.

The noun rus, ruris means the countryside or the country, and one way Latin expresses in the country is with the locative ruri.

So:

• ruri = in the country
• domi = at home
• Romae = at Rome / in Rome

Latin sometimes uses the locative instead of a preposition like in for place where.

You may also see rure in other contexts, but ruri is the classic idiomatic way to say in the country.

Ruri is locative singular.

The locative is a case used mainly for place where, especially with names of towns/cities and a few special words such as:

• domus → domi
• rus → ruri
• humus → humi

So ruri means in the country without needing in.

Quietiorem is the comparative of quietus, meaning:

• quietus = quiet
• quietior = quieter
• quietissimus = quietest

So quietiorem vitam means a quieter life.

Latin often uses a comparative the same way English does, even when the second thing being compared is only implied. Here the implied contrast is with life in the suburb/suburbs or city environment.

So the idea is:

• they seek a quieter life than the one they have now

Because quietiorem must agree with vitam.

Vitam is:

• accusative singular
• feminine
• the direct object of quaerunt

Since quietiorem describes vitam, it must also be:

• accusative singular
• feminine

So:

• vita = life
• vitam = life as a direct object
• quietior = quieter
• quietiorem = quieter, agreeing with a feminine accusative singular noun

Vitam is the accusative singular of vita, meaning life.

It is accusative because it is the thing being sought:

• quaerunt vitam = they seek a life

Then quietiorem modifies it:

• quietiorem vitam = a quieter life

Quaerunt is:

• 3rd person plural
• present tense
• active voice
• indicative mood

It comes from quaero, quaerere, meaning:

• seek
• look for
• sometimes ask or inquire, depending on context

Here it clearly means seek:

• quietiorem vitam quaerunt = they seek a quieter life

Because Latin has no articles like English the and a/an.

That means:

• suburbio can mean in a suburb, in the suburb, or in the suburbs, depending on context
• vitam can mean life or a life
• quietiorem vitam is naturally translated as a quieter life

English has to choose an article when translating, but Latin does not mark that distinction directly.

Latin word order is more flexible because grammatical endings show how words relate to each other.

English depends heavily on order:

• Those people seek a quieter life

Latin can move words around more freely:

• Qui in suburbio manent, interdum ruri quietiorem vitam quaerunt.

This order is natural Latin:

• the relative clause qui in suburbio manent comes first
• interdum sits near the middle
• ruri is placed before quietiorem vitam
• the main verb quaerunt comes at the end, which is very common in Latin

So the order is not random; it is flexible and often used for rhythm, emphasis, and style.

Yes, the comparison is implied.

In English, a quieter life often means a quieter life than the one they have now. Latin works the same way. It does not need to spell out the second term of comparison if the context makes it obvious.

If Latin wanted to state the comparison explicitly, it could use:

• quam = than

But here that is unnecessary, because the contrast with suburban life is clear from the sentence.

Yes. Because Latin word order is flexible, ruri could be placed in different positions without changing the basic meaning.

For example, Latin could also say:

• Qui in suburbio manent interdum quietiorem vitam ruri quaerunt.

But the given order is good Latin and places ruri neatly before quietiorem vitam, keeping the phrase in the country closely connected with what they are seeking.

Grammatically, suburbio is singular.

But English idiom often prefers the suburbs when talking about suburban residential areas. So even though Latin uses a singular noun, natural English may use a plural expression.

That is why a translation may say:

• those who live in the suburbs

rather than the more literal:

• those who live in the suburb

Both reflect the same Latin form, but one may sound more natural in English.