Compare the structures:
1. “It is not true that if Zayd is human, he is a horse.” — denial of the conditional claim.
2. “If Zayd is human, he is not a horse.” — affirmation of a conditional with a negative consequent.
Both concern horsehood, but the scope of negation changes their logical operation. Identifying a negative word is insufficient; we must ask whether it denies the whole conditional connection or belongs inside the consequent.
This becomes important when we later examine quantifiers and truth conditions for conditional propositions.