I am studying Korean language.

She is nursing her sick grandmother.

She has a keen sense of language, and can quickly grasp the nuances of words.

It's important to enjoy cooking by fully using your five senses.

His five sense organs are very sharp.

These two parts have interchangeability.

These two software are completely interchangeable.

He fought a court battle to gain custody of his child.

She undertook the custody and care of the child.

Please tell me the stem of this word.