1. The next few years, you will grow in and out.

Question

2. The next few years, you will grow mentally and physically.

(Does #1 mean #2?)

3. He is going to New York tomorrow.
4. He will go to New York tomorrow.
5. He goes to New York tomorrow.

(Are the three sentences the same?)

Answer 1

# 1 is not correct because the meaning is not clear.
For # 2, it would be better to say, "In the next few years you will grow both mentally and physically.

#s 3, 4, and 5 are all correct and mean the same.