First, I think will not greet you, because you thought that seems to be younger than me.
ผลลัพธ์ (ภาษาอังกฤษ) 2:
At first, I did not say hello to you. I think you are younger than me.
ผลลัพธ์ (ภาษาอังกฤษ) 3:
At first, I will not say hello to you because I thought you would be younger than me.