Question
'How about joining the school festival?' 'How about joining the school market?' sounds strange to me when used to mean 'How about coming to the school festival/market?'
'Joining' sounds more like they want you to help organize it, do an event, run a stall.

Period one when Grace says to her Dad 'Let's go and see the concert'.  Dad finally replies 'OK.  I will join you.'  This sounds strange in this context as Grace wasn't asking him to join her and her sister, but was asking if they could go together.

It would make sense (to me) if Grace had said 'We are going to the concert.  Can you come too? (Can you join us?)'.  Then Dad's 'I will join you,' would sound OK.

As a non-American there are some phrases which sound strange to me but may be normal American English.  Is this the case here?  Or is it awkward use of English?
Thanks

Thanks jerica725.  Good to know my English isn't too bad.  Sometimes I begin to doubt myself.

Here is an activity we are going to try with the grade 6s for period 4 of this unit.  Easily adaptable to other lessons and grades.  It has worked OK with the grade 5 students.  Here's hoping it works with the grade 6s.

1)   Number each sentence (line). 
2)   Students choose two adjacent lines and write them. (ie lines 1&2, 3&4, 5&6, 7,8 &9, 10&11, 12&13, 14&15)
3)   They must write that/those sentence(s)/line(s) in their notebooks [writing practice]
4)   Then walk around the classroom and try to find the rest of the story.  When you meet a partner read your two lines.  They read their lines.  If they don’t have your sentences you can join the group – in order.
5)   Practice reading in your group (of 5) – and memorizing.
6)   Any groups that got a complete story - perform/Read/Recite to the class.
[Note – it may not be possible to make a complete story as some sentences may not have been written!]
If time – students should choose 2 different sentences and repeat the activity.

It doesn't really matter how many sentences the students have to write but it is probably good to determine where the breaks are otherwise you will have missing sentences or doubled up sentences.

I have added the ppt which might make it easier for the students to see what they are to be copying.  Also the paper they can write on for the 3 rounds.  Otherwise they could write in their notebooks, or on the edge of the pages in their textbook.

Holiday quiz made by alistairrwillis that I tweaked a little.  Last question is about your birthday.  12 questions.

기결문 취소 안 되신 분이 있습니다.
부탁드립니다.^^

Thanks hangook77
It was more the 'joining' part of the sentence.  I would be more likely to say 'How about coming to the school festival?' (if I want them to watch) or 'How about taking part in the school festival?  How about participating in the school festival?' (if I want them to do something).