Can you check these sentences for me?

[bbmak]

Can you check my grammar?
=====verbal modifier=================
1. Retarded, irrational, people always think that “new and improved” means better.
2. Always bent by weasel words, advertisement messages often mislead people to buy.
3. Misled by the word “help,” people often think “help” means stop, cure, and solve, but in reality, the word means to aid or assist.
4. To protect themselves from the claims that they make, advertisers carefully use the weasel words, so they can say things that are not necessarily true.
5. Weasel words are more about feeling than fact, about style than substance, used to smooth over an uncomfortable fact.
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which one should i use?
I have no idea what they has improved not until I read the little, tiny footnote on the right bottom corner.
I have no idea what they has improved until I read the little, tiny footnote on the right bottom corner.

[Ouisch]

"Retarded" is considered highly offensive. In the context of your sentence, perhaps "gullible" is a better choice of words.

[bbmak]

Ic thank you so much for checking.

what about the grammar of the sentences? My sentences make sense?
and
which one should i use?
I have no idea what they has improved not until I read the little, tiny footnote on the right bottom corner.
I have no idea what they has improved until I read the little, tiny footnote on the right bottom corner.

[Tdol]

I had no idea what they had improved until...