Even though it was the main purpose of their lessons, Midii was still very careful how she explained herself to Jor-El. Secrets were fewer and fewer kept the longer she spent in Keelai, but the paranoia of the ones she had left still had a hold on her.

"I can understand up to 60% on my own now."

It was not a lie, but she made it seem like such an accomplishment...considering she had already known up to 50% at the start. The only "lie" was to hide her disappointment at not learning faster.