I shall endeavor to create this sentence for you.
I think you mean endeavor. I will endeavor to explain. That is a bold endeavor.
To do something in vain means that you do not succeed in doing what you are trying to do; to try in vain is to fail.
in vain means the expected result is not going to happen
No. Demanding is needing alot of attention. An endeavor is an attempt to do something.
I think you mean "vain".
for no point
Vain means conceited, or it may mean to no avail. Here are some sentences.She tried in vain to stand on her head.He was as vain as a peacock."You're so vain!" (a song by Carly Simon)
To die in vain means that you died for a cause but your death did not change anything.
Without effect or to no purpose
Conceited means having an excessively favorable opinion of one's abilities, appearance, or accomplishments. It implies being vain or excessively proud.
Vain