The rule:
To be + going to + infinitive verb
-> To be: 1. Am 2. Is 3. Are
I -> AM going to play tennis with my friends.
You -> ARE going to watch a movie with Chris.
He -> IS going to
She -> IS going to cook pizza for dinner
It -> IS going to
We -> ARE going to help the old lady.
They -> ARE going to
As you can see above I already gave some examples. It is important to look at he I, he/she/it, we and they pronouns before you decide to put the correct form of to be.
To be form -> in black
going to -> in blue
infinitive verb -> in orange
As you are making sentences you can also add 'not' between the to be form and going to.
I am going to be watching a movie with a friend. -> FOUT
I am going to watch a movie with a friend -> GOED
*Uitleg
Regel is -> To be + going to + infinitive
EN NIET -> To be + going to + be+ing
https://www.youtube.com/watch?v=juhyvurt6Jw