Invitations are written when you want to invite others on a variety of occasions both in personal life and in business. They fall into two categories: invitation cards and invitation letters.

Invitation cards are usually given for formal banquets and important receptions. They are printed on cards or high quality fancy paper. An invitation includes the key points: the name of the hosts, name of the guests, the event, time, date and place, all of which are centered in separate lines. In the bottom line, an invitation lists RSVP and contact information. The RSVP implies that the invited guests need to give an immediate reply. Sometimes an invitation includes “regrets only”. It means a reply is required only the guests cannot attend.

An invitation letter is similar to a business letter. Formality depends on the relationships between the writer and the reader. It usually includes three parts. First, you invite the reader, telling him (her) the event, time and place. Second, you briefly introduce the arrangements. Third, you express your wishes for the guests to accept your invitation.

When receiving an invitation, you need to give a reply in time. If you receive an invitation card, you need to reply in the same style. If you receive a letter, reply with a letter form. When you cannot attend, you need to decline the invitation with an explanation in any case.

邀请函是为了邀请客人参加某个具体活动而发出的信函。有请柬和书信两种形式。请柬格式严谨、措辞规范。通常会印刷在质地优良的A5或A6纸张或卡片上。适用于大型活动，如宴请、庆典、大型会议等。书信形式的邀请函既可用于邀请客人参加正式的大型活动，也可用于朋友之间的活动。具体采用哪种形式取决于活动性质以及邀请人和被邀请人之间的关系。邀请函应提前一到两周发出。被邀请人收到邀请之后，应及时回复。