iyo
your

Ano ang iyong pangalan?
What is your name?

iyon
that

Ano ang sinabi mo?
What did you say?

Anong iyong sinabi mo?
What was it that you said?

Anong ang ginawa nila?
What did they do?

Anong iyong ginawa nila?
What was it that they did?


The word iyong in the second sense (conjugation of iyon) is
often shortened to 'yong or 'yung in conversation.

Anong 'yung ginawa mo?
What was it that you did?