WILL and BE GOING TO

We often find difficulty using WILL and BE GOING TO in our daily lives. As a foreign language, although we use it less, we need to learn how to differ those two verbs.
Let's see the difference:
example 1 :
"Dana is ill. She's now in the clinic."
"Oh, poor her. I will see her this afternoon after school."

example 2 :
"Dana is ill. She's now in the clinic."
"Yeah, I know. I'm going to see her this afternoon after school."

conclusion: We use BE GOING TO if we have planned it.

Exercise: Decide whether they use WILL or BE GOING TO.
1. "Far, your cellphone rings..." "I_____get it..."
2. Hana _____visit her uncle in Jember. He has saved some money.
3. We don't know where to go. What_____we____do?
4. The children are swimming in the river. Their moms _____surely be mad.
5. Lovita and Ganis are not my neighbors anymore. They have moved, but if you need to see them, I _____take you there.

Answer Key:
1. will (commonly pronounced 'll)
2. is going to
3. are--going to
4. will
5. will