Wait, I forgot my wallet! I (a. will go back / b. am going to go back) home to get it.

 The weather forecast says it (a. will snow / b. is going to snow) tomorrow. Let’s build a snowman! 

 I promise I (a. will call / b. am going to call) you as soon as I arrive. 

 Look at the traffic jam! We (a. will miss / b. are going to miss) the flight if we don’t hurry. 

 My boss (a. will retire / b. is going to retire) next year. He announced it in the meeting yesterday.