The French you learn in school is not at all the same language as what you encounter when speaking to people in real life - there are all kinds of shortcuts, informalities, and other differences that you need to be familiar with in order to carry on a conversation. Check out some resources that focus on how French is actually spoken.
A transference error is a certain type of mistake, common to foreign language learners, which can be particularly difficult to stop making. The hardest part is becoming aware of the error; once you’ve done that, it’s just a matter of figuring out the correction and practicing your way to perfection.
Learn French by following the adventures of Victor Hugo as he explores the Francophone universe. The humorous videos and comics are suitable for post-beginners aged 15 and up, and include a variety of accents as well as slang.