Matri displicet clamor qui extra domum manet.

Because displicet works with the dative for the person who feels the reaction.

So in this sentence:

• matri = to the mother
• clamor = the thing that is displeasing

Latin says this idea as:

• The noise is displeasing to the mother

where English often prefers:

• The mother dislikes the noise

So mater would be nominative and would make mother the subject, but here clamor is the subject.

The subject is clamor.

You can tell because:

• clamor is nominative singular
• displicet is 3rd person singular

They match.

So grammatically, Latin is saying:

• clamor displicet matri = the noise displeases the mother

not

• the mother displeases the noise

It is singular because its subject, clamor, is singular.

Latin verbs agree with their subject in number and person. Since there is one clamor, the verb is displicet.

If the subject were plural, you would expect a plural verb, for example:

• clamores matri displicent = the noises displease the mother

Not exactly. More literally, displicet means is displeasing or does not please.

So:

• matri displicet clamor literally = the noise is displeasing to the mother

But natural English often turns that into:

• the mother dislikes the noise

This is a very common thing to remember with placet and displicet:

• placet alicui = is pleasing to someone
• displicet alicui = is displeasing to someone

Qui is a relative pronoun, meaning who, which, or that.

Here it refers back to clamor. So:

• clamor qui extra domum manet
• the noise that remains outside the house

A useful rule:

• a relative pronoun gets its gender and number from the noun it refers to
• but its case depends on its job inside the relative clause

Here qui refers to clamor, so it is:

• masculine singular because clamor is masculine singular

And it is nominative because inside its own clause it is the subject of manet.

Because clamor is masculine, not neuter.

The forms are:

• qui = masculine nominative singular
• quae = feminine nominative singular
• quod = neuter nominative singular

Since clamor is masculine, the relative pronoun must be masculine too:

• clamor qui...

not

• clamor quod...

Domum is accusative singular.

The preposition extra takes the accusative, so:

• extra domum = outside the house

That is the normal construction.

Also, domus is a somewhat irregular noun, but here you only need to notice that extra wants the accusative, and domum is the accusative form.

Manet means remains, stays, or lingers.

So the relative clause:

• qui extra domum manet

means something like:

• which remains outside the house
• which stays outside the house

Compared with a simple is outside, manet can suggest continued presence: the noise is not just outside for a moment; it is still there.

Latin word order is much more flexible than English word order because Latin uses case endings to show the grammatical relationships.

In this sentence:

• matri is dative
• clamor is nominative
• qui introduces the relative clause

So Latin does not need to rely on a fixed English-style order.

This sentence could be rearranged without changing the basic meaning, for example:

• Clamor qui extra domum manet matri displicet

That may look more familiar to an English speaker. The given order, with matri first, may give a little emphasis to the mother.

Because Latin has no articles.

Latin does not have separate words for:

• the
• a/an

So clamor can mean:

• the noise
• a noise

and domum can mean:

• the house
• a house

The context tells you which English article makes the most sense.

Look at what qui is doing inside its own clause:

• qui extra domum manet

Here qui is the one performing the action of manet. In other words, the noise remains outside the house. That makes qui the subject of manet, so it must be nominative.

This is an important principle with relative pronouns:

• gender and number come from the antecedent
• case comes from the pronoun’s function in its own clause

So qui is:

• masculine singular because of clamor
• nominative because it is the subject of manet

Yes. A very literal version would be:

• To the mother, the noise which remains outside the house is displeasing.

That sounds stiff in English, but it shows the Latin grammar clearly:

• matri = to the mother
• displicet = is displeasing
• clamor = the noise
• qui extra domum manet = which remains outside the house

A more natural English translation usually changes the structure:

• The mother dislikes the noise outside the house.
• The mother dislikes the noise that remains outside the house.

Both are trying to express the same Latin idea.