Introductions - Social Language

There are a number of phrases that are commonly used to introduce strangers.

(name), I don't think you've met (name).
I don't think you know (name)
May I introduce you to (name)
(name), do you know (name)?
(name), I'd like you to meet (name)

When you meet someone the first time, it is common to greet the person with "How do you do?" the correct response is "How do you do." Here is a short introductory conversation:

Ken: Peter, I'd like you to meet Mary.
Peter: How do you do?
Mary: How do you do.
Ken: Mary works for ...

A variation is also "It's a pleasure to meet you." or "Pleased to meet you."

Ken: Peter, I'd like you to meet Mary.
Peter: It's a pleasure to meet you.
Mary: How do you do.
Ken: Mary works for ...

Ken: Peter, I'd like you to meet Mary.
Peter: How do you do?
Mary: Pleased to meet you.
Ken: Mary works for ...

In informal situations, especially in North America, introductions are also made simply saying: "This is (name)." It is also common to just say "Hi" or "Hello" as a response in this informal setting.

Ken: Peter, this is Mary.
Peter: How do you do?
Mary: Pleased to meet you.
Ken: Mary works for ...

It is also quite common to shake hands when you are introduced. After the initial introduction, hand shaking generally takes place in more formal, business situations. Otherwise, people just say "Hi."

By Kenneth Beare, About.com Guide