Welcome to the forum, toutoublue.
Are you really a Chilean whose native language is Chinese and who now livesin France? If not, please amend your profile.
1. "as you did the last time" or "as you did last time". Which one is correct and natural ? - ... as you did/made last time. 'The' is not incorrect, but I think the sentence is more natural without it.
2. Is it OK if I say "you make the same mistake as last time" ? No - 'You are making ...' or 'You have made ...'
3. "I told you he isn't " or "he wasn't" ? I'm wondering which tense I should apply here. Both are possible, but 'wasn't' is more likely.
ps. What's a 'homegirl'?
Student or Learner