Please check-I had to correct the first sentence to make it correct in the second

No hablé con alguien en la escuela
No, hablé con nadie en la escuela.

To determine whether the correction "No, hablé con nadie en la escuela" is correct, we need to understand the meaning of the original sentence "No hablé con alguien en la escuela."

In the original sentence, "No hablé con alguien en la escuela," the word "alguien" means "someone." Therefore, the sentence translates to "I didn't speak to someone at school."

Now, let's examine the correction "No, hablé con nadie en la escuela." In this corrected version, the word "nadie" means "nobody." So, the correction translates to "I didn't speak to anybody at school."

Both translations essentially convey the same meaning, which is that the speaker did not have a conversation with anyone at school. Thus, the correction "No, hablé con nadie en la escuela" is indeed correct.