What you have to do is look at your mistakes, correct them, and write down what the mistake was, why you did it, and how you fixed it.
-auditor is a false cognate, use audience.
-he and him is gender biased, use gender free terminology.
-The verb tell is used 3 times in the same sentence.
-There should be a comma ',' between the last 2 clauses. And is not simply separating nouns
The sentence could be re-written differently:
Yannick Daoudi tells the audience that everyone can make a difference, Ernesto Sirolli explains
how to do so, and David Damberger warns that it is normal to fail.
-People is the subject of neglect and forget, and people is always plural, the verbs do not require an 's'.
-Succeeded, not succeded.
-First, avoid direct questions in formal texts. Second, use correct structure:
How can one be sure? Wh-word-auxiliary-subject-verb-object?
or (with the verb to be): Wh-word-verb-subject-object?
-our is a first person possessive adjective, use third person (in formal texts) like their
- isn't is a contraction, use full verb form in formal written: is not
Using had failed in this sentence is not justifiable. The past perfect needs to be used in relation to another action or event in the past.
If you want to use a past perfect:
There were a lot of humanitarian interventions that had failed (before another action or event in the past).
Or, use a persent perfect:
There are a lot of humanitarian interventions that have failed.