Learn Finnish: Me emme saa lupaa äidiltä. - We do not get permission from mother.

Äidiltä is in the ablative case, which adds the ending -lta or -ltä to mean 'from'. We use this case when receiving something from a person. Notice also the consonant change: the strong t in äiti softens to a d when we add the ending, making it äidiltä.

Why is the word for permission lupaa instead of the basic form lupa?

Lupaa is in the partitive case. In Finnish, if a sentence is negative (like emme saa, 'we do not get'), the object of the sentence must be put into the partitive case.

How does the negative verb work in emme saa?

To make a verb negative in Finnish, you conjugate the negative word to match the person. For 'we', the negative word becomes emme. The main verb (saada, to get) drops its personal ending, so saamme (we get) simply becomes emme saa (we do not get).

How would I ask 'Who do we not get permission from?' using this grammar?

You would use the question word keneltä (from who). Because the person we receive something from takes the -lta or -ltä ending, the question word must do exactly the same: Keneltä me emme saa lupaa?