How to say, "When I..."

I don't quite know how to add question words to Spanish sentences.
I was wondering how I could do the following:

1. When I have free time I like to read a book.
2. I write notes when I read a book.
3. When I don't understand something, I ask a question.
4. When I don't hear the answer, I repeat the question.

I know some of the verbs and vocabulary.
However, I don't know the grammatically correct way to link all of them.
I'm trying to focus on how to put "when" into a sentence.
I want to put "when" into different areas of the sentence.

Let me take a stab at #3:
Cuando no comprendo cosas, yo pregunto una pregunta.

I'll try #4:
Cuando no escucho la respuesta, yo pido la pregunta.


I guess another example of the information I'm looking for would be this:
1. How do I know what I'm looking for?
My try at translating: ¿Cómo sabo que buscar?

I'm assuming "hacer" and "formular" would be "to make" and "to formulate."

However, what is wrong with using "preguntar"?

I'm asking a question. I'm not formulating or making a question. I believe formulating or making a question would occur in my mind, brain, or thought. The act of speaking aloud is what is being emphasized, not the generation of a question in my mind.

If someone would be so kind, could someone explain why my translations were incorrect? Well, besides the accent marks.

Muchas gracias para la información, Crom.