I stayed at home to watch over my sick grandmother.

She is in charge of watching over the patients at the hospital.

I had a good time having fun talking with my friends.

He is studying Chinese.

She is nursing her sick grandmother.

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

This equation needs a minus sign.

This data is encoded, so special software is needed to decode it.

He created a program to encode the message.

My father is fifty years old.