Gravis iniuria etiam fideli socio displicet.

The subject is gravis iniuria.

• iniuria is a nominative singular feminine noun.
• gravis is also nominative singular feminine, agreeing with iniuria.

So gravis iniuria is the thing that displeases.

Gravis is an adjective meaning serious, heavy, or grave.

It appears as gravis because it must agree with iniuria in:

• gender: feminine
• number: singular
• case: nominative

Since iniuria is feminine nominative singular, the adjective also takes the feminine nominative singular form gravis.

Because displicet takes the person affected in the dative case.

So:

• socio = to/for an ally, companion
• fideli agrees with socio, so it is also dative singular

This is different from English, where we say displeases a faithful ally, with no special case ending visible. In Latin, the person who experiences the displeasure is put in the dative.

So fideli socio means to a faithful ally or more naturally in English, a faithful ally.

Displicet literally means is displeasing to.

Its basic pattern is:

• the thing causing displeasure = nominative subject
• the person displeased = dative

So in this sentence:

• gravis iniuria = the thing that is displeasing
• fideli socio = the person to whom it is displeasing

This is the same kind of construction as placet (is pleasing to).

The dictionary form is displiceo, displicere, displicui.

Displicet is:

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

It means he/she/it displeases or is displeasing.

Because the subject gravis iniuria is singular, the verb is singular too.

Latin word order is much freer than English word order because the endings show grammatical function.

Placing the verb at the end is very common in Latin, especially in straightforward prose. So:

• Gravis iniuria etiam fideli socio displicet

is a normal Latin arrangement.

Latin can move words around for emphasis, style, or rhythm, without changing the basic meaning.

Etiam usually means also, even, or still, depending on context.

In this sentence, it most naturally gives emphasis to fideli socio:

• even to a faithful ally
• more naturally in English: even a faithful ally

So the sense is that a serious wrong is so offensive that even someone loyal or faithful dislikes it.

Yes, grammatically it could, because etiam can mean both also and even.

But the context usually decides which is better.

Here, even is often the more natural choice, because it emphasizes surprise:

• a serious wrong displeases even a faithful ally

That suggests that a faithful ally might normally be expected to be more tolerant, but not in this case.

Iniuria is nominative singular feminine here.

You can tell because:

1. it is the subject of the verb displicet
2. its adjective gravis agrees with it
3. the sentence needs something in the nominative to be the thing that displeases

Its dictionary form is iniuria, -ae, a first-declension noun.

Socio comes from socius, meaning ally, companion, associate, or partner.

Here it is dative singular:

• socius = nominative singular
• socio = dative singular

Because displicet governs the dative for the person affected, Latin uses socio, not socius.

Yes. Fideli agrees with socio.

Both are:

• dative
• singular
• masculine here by sense, because socius is masculine

So fideli socio means to a faithful ally.

The adjective fidelis, fidele is a third-declension adjective, and its dative singular form here is fideli.

Because Latin often shows relationships through case endings instead of prepositions.

In English, we may think of the phrase as to a faithful ally, but Latin expresses that simply by the dative ending:

• fideli socio

No separate word for to is needed.

Yes. Putting the adjective before the noun is very common in Latin.

So gravis iniuria is a normal way to say a serious wrong/injury.

Latin can also reverse the order:

• iniuria gravis

That would still mean the same thing, though the emphasis or style may feel slightly different.

Because the subject is singular:

• gravis iniuria = a serious wrong/injury

Since there is only one subject, the verb is 3rd person singular:

• displicet = displeases

If the subject were plural, the verb would be plural as well.

A very useful pattern is:

[thing in nominative] + [person in dative] + displicet

For example:

• hoc mihi displicet = this displeases me
• consilium amicis displicet = the plan displeases the friends

So this sentence teaches an important Latin structure:

• the thing is the grammatical subject
• the person affected goes in the dative