Greeting is an act of communication in which human beings intentionally make their presence known to each other, to show attention to, and to suggest a type of relationship (usually cordial) or social status (formal or informal) between individuals or groups of people coming in contact with each other. Greetings are sometimes used just prior to a conversation or to greet in passing, such as on a sidewalk or trail. While greeting customs are highly culture- and situation-specific and may change within a culture depending on social status and relationship, they exist in all known human cultures. Greetings can be expressed both audibly and physically, and often involve a combination of the two. A greeting, or salutation, can also be expressed in written communications, such as letters and emails.

In some languages and cultures, the same word or gesture is used as both greeting and farewell. Examples are "Good day" in English, "Sat Shri Akaal" in Punjabi, "As-Salamualaikum" in Arabic, "Aloha" in Hawaiian, "Shalom" in Hebrew, "Namaste" in Hindi and "Ciao" in Italian. The bow and handshake are also used for both greeting and leave taking.

A greeting can consist of an exchange of formal expression, kisses, handshakes, hugs, and various gestures. The form of greeting is determined by social etiquette, as well as by the relationship of the people.

Beyond the formal greeting, which may involve a verbal acknowledgment and sometimes a hand shake, facial expression, gestures, body language and eye contact can all signal what type of greeting is expected. Gestures are the most obvious signal, for instance greeting someone with open arms is generally a sign that a hug is expected. However, crossing arms can be interpreted as a sign of hostility. Facial expression, body language and eye contact reflect emotions and interest level. A frown, slouching and lowered eye contact suggests disinterest, while smiling and an exuberant attitude is a sign of welcome.

I am going to talk today about…(Hôm nay tôi sẽ nói về)

· The purpose of my presentation is… (Mục đích bài thuyết trình của tôi là…)

· I’m going to take a look at… (Tôi sẽ xem xét về…)

· I’m going to give you some facts and figures… (Tôi sẽ đưa ra cho quý vị một vài sự kiện và con số…)

· I’m going to concentrate on… (Tôi sẽ tập trung vào…)

· I’m going to fill you in on the history of… (Tôi sẽ cung cấp thông tin về lịch sử của…)

· I’m going to limit myself to the question of… (Tôi sẽ tự giới hạn cho câu hỏi về…)