The Genitive Case

What word would be genitive in English? Captain America took the shield from Ironman's lair.

Which word would be genitive in English? The enemy of Batman is the Joker.

The word river in Latin is fluvius. How would I say 'of the river'?

The plural of rivers is 'fluvii.' But how would I say 'of the rivers?'

The word for maid is ancilla. How would I say 'of the maid?'

How would I write the 'master of the maids?' Plural

How would I say the 'mother of the daughter?'

How would I say 'a great number of towns' Remember: A great number would be NORMAL.

How would I say: "A small number of rivers?"

How would I say "the rivers of the big province"? Think about what big is modifying.

On a scale of 1 (not at all) to 5 (very well), how do you feel about genitive forms so far?