About a relative adverb!

[jiyoun01]

Hi, I'm Jiyoun living in South Korea, and I got a question ! Please help me.

I've learn that these followings are correct.

ex) We need to have some opinions which creative ideas can be encouraged by.
We need to have some opinions that creative ideas can be encouraged by.
We need to have some opinions creative ideas can be encouraged by.
We need to have some opinions by which creative ideas can be encouraged.
We need to have some opinions where creative ideas can be encouraged.

Howerver, is it okay to turn 'where' into 'that' without a preposition(by) at the end of the sentence? In other words,

We need to have some opinions that creative ideas can be encouraged.

Is it corret? Then, is the following wrong?

We need to have some opinions that creative ideas can be encouraged by.

I'm so confused. Please help me!!!

[Raymott]

hi, i'm jiyoun living in south korea, and i got a question ! please help me.

i've learn that these followings are correct.

ex) We need to have some opinions which creative ideas can be encouraged by. Terrible, but grammatical.
We need to have some opinions that creative ideas can be encouraged by. Not much better
We need to have some opinions creative ideas can be encouraged by. No, too confusing.
We need to have some opinions by which creative ideas can be encouraged. This is probably the best of a bad lot. It's grammatical. I don't like the concept of needing opinions by which creative ideas are encouraged though. If the ideas are creative, they don't need opinions to encourage them. It's not a very natural sentence.

We need to have some opinions where creative ideas can be encouraged. - Wrong. Not possible grammatically.

but is it okay to turn 'where' into 'that' without a preposition(by) at the end of the sentence? in other words,
You can't change "where" into "that". But that's not the issue. The sentence with "where" is wrong.

We need to have some opinions that creative ideas can be encouraged. Wrong.

is it corret? then, is the following wrong?

We need to have some opinions that creative ideas can be encouraged by.
No, it's not wrong; it's just a strange sentence.

i'm so confused. please help me!!!

"We need to have a range of different opinions to encourage students to think for themselves." It will be the people with creative ideas that will give the opinions.

[5jj]

Welcome to the forum, jiyoun.

Please follow the standard convention and use a capital letter for 'I', the first person pronoun.

[jiyoun01]

Thank you very much for this!
I've learned English for almost 20 years, but I really haven't known that!
So thank you!

[emsr2d2]

Thank you very much for this!
I've learned been learning English for almost 20 years, but I really haven't known didn't know that!
So Thank you!

In 20 years you've never noticed that the word "I" is always capitalised?!

[Raymott]

In 20 years you've never noticed that the word "I" is always capitalised?!

This can happen to someone who talks but never reads.