# A structural quetion of a sentence

Today,when my English teacher helped me and my classmates to scan through the chapter one in the volume one of Harry Potter,she asked us to write a composition. However,the topic she wrote was a little odd to me.

She wrote：

Tell one thing that Ms.Dursley was afraid of the Potters.

To be honest,I knew what she wanted to say was 「tell one of the reasons Ms.Dursley was afraid of the Potters」. Thus,I really believed its structure had a grammatical error. And then,I told her that she should correct it to the sentence "tell one thing that Ms.Dursley was afraid of the Potters for ". Notwithstanding,she said she didn't understand why the sentence needed "for" at the end. So, isn't there the error in her sentence?Why or why not?

If it had errors,how to correct it in the best way?

• As a native English speaker, I completely agree with you that there is an error. I don't know the official grammatical reason, but there is an error.
– 米凯乐
Dec 8, 2018 at 14:41
• @米凯乐 thanks for support.xd yeah…To explain the error is always a challenging mission for me.:( Dec 8, 2018 at 14:47
• It's a relative construction where "that" is a relative pronoun that has "thing" as antecedent. The ungrammaticality arises because "that" has no function in the relative clause: it can't be subject ("Ms Dursley" is the subject), and it can't be the object (there's no transitive verb), and it can't be complement of the preposition "of" ("the Potters" has that function). One solution is to insert a preposition such as "about" at the end. "That" would then assume the function of its complement, and the sentence would make sense. Dec 8, 2018 at 16:29
• @BillJ I agree with you. Despite the fact that I thought of "about" and"for" both to be that preposition,can I use "for" instead of "about" in the sentence? Dec 8, 2018 at 16:36
• Yes, and you could also use "over" . Dec 8, 2018 at 16:39

You are correct that the grammar of this sentence is VERY bad.

I would use the word 'made' after 'that', but it is then essential to delete 'was'.

And 'tell' is a poor word choice. Either 'explain' or 'describe' would be better.

Describe one thing that made Ms. Dursly afraid of the Potters.

An alternative would be:

Describe one reason why Ms. Dursly was afraid of the Potters.

• TBH,Good suggestions.：) I can't wait to tell her how to correct. Dec 8, 2018 at 15:07
• But,the biggest problem is that she doesn't think her sentence has any error. Do you have any suggestion for me to explain it？ Dec 8, 2018 at 15:08
• @Chang yo Sorry, I tried and couldn't figure out a way to explain. One point you could make is that the whole of 'Ms.Dursley was afraid of the Potters' is an independent clause - it can exist as a complete sentence on its own. Such clauses can function in the same way a single noun within sentences. You could ask her to how explain how this makes sense: 'Tell one thing that butterfly'. Logically, if her sentence makes sense then that one would too (Yes, it is rubbish too). That's as much as I can say, but don't give up; others should be able to help you more than I can. Dec 8, 2018 at 15:18
• I got it. Anyway, thanks for sparing your time to answer. And,"Tell one thing that butterfly" may be a good way to try.hahaha Dec 8, 2018 at 16:00