I read from an English grammar site that:
1. She taught kids English. (implies that the kids acquired English.)
2. She taught English to kids. (does not imply whether the kids acquired English or not.)

However, I understand that native speakers of English do not clearly distinguish the difference between the above sentences.

My question is:

Does the situation change if "but they did not learn it" is added?


1. She taught kids English, but they did not learn it.

2. She taught English to kids, but they did not learn it.

Are these both used naturally?