A possible concise summary is:
The speaker tells his story of how he left his biotechnology studies in Barcelona and moved to France to work as an au pair and learn French in four months. He shares his method of learning languages, which consists of finding motivation, signing up for an exam, creating a list of high-frequency words, establishing daily habits, and following a study plan. He also recommends Cambly, an online platform to learn English with native tutors. He concludes by saying that learning languages is fun and challenging, and invites the viewers to watch his other videos on the topic.
Here are the key facts extracted from the text:
1. The speaker left biotechnology studies to travel around Europe and learn French.
2. The speaker worked as an au pair in Lyon, France, and learned from the children he took care of.
3. The speaker's goal was to master French in four months and obtain the DALF C1 certificate to enter a French university.
4. The speaker followed a study plan based on the exam methodology and used various techniques and resources to improve his vocabulary, grammar, pronunciation and comprehension.
5. The speaker recommends Cambly as a platform to learn English with native tutors and offers a discount code for his viewers.
6. The speaker emphasizes the importance of motivation, immersion, personalization and fun in language learning.