Learn Hardcore Latin: Pater dicit iniuriam amicitiae nocere. - Father says that a wrong harms friendship.

Breakdown of Pater dicit iniuriam amicitiae nocere.

Why is nocere in the infinitive instead of a finite form like nocet?

Because this sentence uses indirect statement after dicit.

Latin often expresses X says that Y does Z with:

So:

If this were a direct statement, you might have:

But after dicit, Latin changes that into indirect statement:

Why is iniuriam accusative? Shouldn’t the subject be nominative?

Normally, yes: the subject of a normal finite verb is in the nominative.

But in an indirect statement, the subject of the infinitive goes into the accusative. That is exactly what is happening here.

So in the underlying direct statement:

the subject is nominative iniuria.

But in indirect statement after dicit, it becomes:

So iniuriam is the subject of the infinitive , even though it is accusative.