4.Writing-1, 24+1 by may 20
Writing

1. CLB5W Write a formal invitation for a group function (such as a company picnic, BBQ or potluck).
1. Have you ever received a formal invitation to a big event? Look at 10 formal invitations here, and write down 5-6 expressions of politeness or formality. These may include unusual adverbs, key nouns and verbs, and passive verb forms. How are they different from an informal invitation?
2. Think of a group function with some details, and write a formal invitation appropriate to that event.
3. Ask yourself: Did you convey the intended meaning; use language and content appropriate and relevant to the situation; and express main ideas and support them in some detail?

                                         
   1) Yes. I have ever received some formal invitation for my friend's son's /daughter's wedding in China.
  * could. would. can. may. please. thank you very much. 
          Xiaoyun: Hi Susanne! How are you?

          Susanne: I am fine. What about you?

          Xiaoyun: I am great! Wengu and I are celebrating our wedding anniversary next week.

          Susanne: Oh great! Congratulations in advance!

          Xiaoyun: Thank you very much, Susanne. So, can you come over for a small party? It's next week                               on Tuesday.

          Susanne: Sure I can! Thank you for inviting me Xiaoyun.     

          2)
        Mis Susanne
             My husband and I are going to celebrate our thirty wedding anniversary next week .  It would be a great pleasure for us if you could come and join us on this important occasion for our family. The party will be held at the 121 Mcmahon Dr Toronto. ON. at 6:30 pm. 22 June 2016
             We look forward to seeing you that evening. 
                                                                                                                                sincerely
xiaoyun

           3). First is politeness. Then reason, time, and location, all of these are necessary.