首先,这句话的中文理解就是有歧义的.一种理解是一家名叫“史密斯夫人的服装店”里.相对应的翻译是：
1 There are many clothes on sale at Mrs.Smith's boutique.或 Many clothes are on sale at Mrs.Smith's clothing store.
另一种理解是属于史密斯夫人的一家服装店（店名叫什么未知）里.
2 There are many clothes on sale at the botique of Mrs.Smith's.
一楼：少了is
Mrs.Smith's clothing store is selling many low-cost clothes
另外,不要把衣服在廉价出售的意思翻译成便宜衣服在出售.
二楼：用这种结构的话Mrs.Smith's clothing store has many clothes for sale.
某东西 on sale
店里有东西 for sale
根据追问；
There are so many clothes on sale at the Mrs Smith's clothes store.
“the” 不用的时候很普遍,但是也有用the的时候.