Discordia inter amicos vitanda est.

Discordia is nominative singular feminine. It is the subject of the sentence.

So grammatically, the sentence is about discord or quarreling/strife, and the rest of the sentence says what must be done about it.

Because inter is a preposition that takes the accusative case.

So:

• amici = nominative plural, friends as a subject
• amicos = accusative plural, used after inter

That is why Latin says inter amicos = among friends.

Here inter means among or between.

With plural nouns like amicos, it usually has the sense among:

• inter amicos = among friends

It marks the group within which the discord is to be avoided.

Vitanda is a gerundive from the verb vitare, meaning to avoid.

A gerundive is a verbal adjective. Here it means something like:

• to be avoided
• needing to be avoided
• that must be avoided

Because it is an adjective, it agrees with discordia in:

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

So discordia ... vitanda means discord ... to be avoided / that must be avoided.

Because gerundive + est is a standard Latin construction called the passive periphrastic.

It usually expresses necessity, obligation, or something that ought to be done.

So:

• vitatur = is avoided
• vitanda est = must be avoided / is to be avoided

That is an important difference. The sentence is not merely describing what happens; it is expressing what should happen.

Because vitanda is an adjective, even though it comes from a verb.

In Latin, adjectives agree with the nouns they describe in:

• gender
• number
• case

Since discordia is feminine nominative singular, the gerundive must also be feminine nominative singular:

• discordia vitanda est

If the noun were different, the gerundive would change too.

Yes. Latin word order is much more flexible than English word order.

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

• Discordia inter amicos vitanda est
• Inter amicos discordia vitanda est
• Vitanda est discordia inter amicos

The chosen order is natural and clear. Latin often places the verb est at or near the end, and it also often puts important descriptive words like vitanda in a prominent position.

Yes, in a general sense.

With the passive periphrastic, Latin can add a dative of agent to show who has the obligation. For example:

• nobis discordia inter amicos vitanda est = we must avoid discord among friends
• literally, discord among friends is to be avoided by us

In your sentence, no agent is stated, so the idea is general:

• discord among friends must be avoided

They are similar in meaning, but not identical in feel.

• vitanda est = must be avoided / is to be avoided
• debet vitari = ought to be avoided / should be avoided

Both can express obligation, but the gerundive construction is a very characteristic and elegant Latin way to express necessity. It often sounds more compact and more idiomatic in formal Latin.

A very literal breakdown would be:

• discordia = discord
• inter amicos = among friends
• vitanda est = must be avoided / is to be avoided

So the structure is essentially:

Discord among friends is to be avoided.

That literal understanding helps show how the Latin grammar works, even if smoother English might phrase it a little differently.