Rudus sub nucleo est.

The rubble layer lies beneath the fine bedding layer.

Breakdown of Rudus sub nucleo est.

• esse: to be
• sub: under
• nucleus: the fine bedding layer
• rudus: the rubble layer

Questions & Answers about Rudus sub nucleo est.

What case is rudus, and what job is it doing in the sentence?

Rudus is nominative singular here, and it is the subject of est.

A quick way to see that:

• est means is
• the thing that is something or is somewhere is the subject
• so rudus is the thing being talked about

So the structure is basically:

• rudus = subject
• sub nucleo = where it is
• est = is

Why is it nucleo instead of nucleus?

Because sub here takes the ablative case, and the ablative singular of nucleus is nucleo.

So:

• dictionary form: nucleus
• ablative singular: nucleo

This is very common in Latin: a noun changes its ending depending on its role in the sentence.

Why does sub take the ablative in this sentence?

With sub, Latin often distinguishes between:

• place where something is → ablative
• motion toward/under something → accusative

In Rudus sub nucleo est, the sentence describes , not movement. The rubble is already there. So Latin uses: