When you meet someone you don’t know, or don’t familiar with, you should say 

• How do you do?

We often say “How do you do?” to someone you first meet or don’t familiar with. 

This word has the same meaning as “hi or hello” but do not require answer.

Generally, we respond by saying “How do you do?”.

• Example 1

Mr. Sam : Good morning, Mr. Jack. I’m glad to meet you.

Mr. Jack : Good morning, Mr. Sam. I’m glad to meet you, too.

• Example 2

Mr. Smith : Good afternoon, Mr. Joey. Nice to know you.

Mr. Joey    : Good afternoon, Mr. Smith. Nice to know you, too.

• Example 3

Mr. Tom : Good evening, Mr. Jim. Nice to meet you.

Mr. Jim   : Good evening, Mr. Tom. Nice to meet you, too.

• Example 4

Bobby : How do you do? Pleased to meet you. 

Aliz   : How do you do? Pleased to meet you, too.

• Example 5

Linda : Good morning. My name is Linda. How do you do? 

Jerry : How do you do? I’m Jerry Smith.

Linda : How do you do?