Does your English level improve during an exchange year? Yes.
First of all, yes, a notable evolution of the level of English is to be underlined through Erasmus.
Before I left, I thought that I had a very good level of English, that it would not take much to make me bilingual. With hindsight, I now realize that this vision was inaccurate. It is true that I was able to have conversations in English with foreigners without worrying and that I could present a class assignment without really having to practice. Indeed, I could state my opinion on various topics and tell factual stories. However, I realized when I arrived in a world where speaking English is not limited to the four walls (or the zoom link) of the English class, that I was very far from being bilingual. Indeed, it was no longer a matter of speaking English for a few hours a week but several hours a day. Being a talkative person by nature, I particularly like to tell anecdotes and add a lot of details to reinforce the comical potential of these parts of my life. That's why it was frustrating at the beginning to be content with just the broad outlines of the story that I was dying to make more elaborated.
The question of humor came up very quickly: how to make people laugh in English? How to be funny when you have to stop in the middle of your story because you can't find the right word? We launch into an attempt to define the word to avoid going through the "google translation" process. As time went on, I became more and more comfortable speaking English. Indeed, I could see that most of the French people I knew preferred to stay between French people. This reaction is completely normal because the difficulties to express ourselves in English and the difference of culture and therefore of references complicate interactions. I wanted to meet international people to improve my level of English and to learn more about other ways of life and thinking than the French one I know. Words and expressions that I had learned in school and that I did not use spontaneously became part of my daily vocabulary over time. I also quickly learned a lot of words that I didn't know and that I ended up using every day, like the lexical field of cooking for example. When you are in a situation where you speak English all the time, learning words is no longer a matter of getting good grades, but rather the solution to express yourself fully.
Most of the people I know are bilingual in English. Also, it's very interesting because they use words and expressions that I don't know, all the time. I always try to ask them what it means so that the next time someone uses it, I can recognize the word and gradually add it to my vocabulary. Having a lot of extracurricular activities also takes my vocabulary up. In sports classes (badminton, table tennis, squash), I learn the appropriate vocabulary. When I'm in my Photoshop class I learn a more precise vocabulary of actions and tools to use to create pictures and when I'm, for example, cooking with friends, I learn a lot of names of various foods, cooking utensils, and verbs related to cooking.
Also, I indeed feel a real evolution of my English level. Now I don't have to think before speaking in English and the words come out by themselves. My accent has improved and the people I met when I arrived in September also informed me that they had noticed a real change in the way I express myself. The sentences are more fluent, the vocabulary richer. This positive evolution leads me to believe that with the time and the months I have left to spend here, I will be able to improve my English even more.
Also, the fact that I am taking classes in English and therefore reading documents and writing in English is a driving force in my journey to become bilingual. In the many group projects we do, we have to express our ideas in English. This takes us to specific vocabulary related to business with precise terms linked to finance for example.
In general, speaking English with people of different levels and accents increases our level of understanding of the language and our ability to understand all kinds of interlocutors. So have no fear after a year abroad, you can be sure that your level of English will improve.
The advice to follow: don't take the easy way out by staying only with French people, but talk to people of different nationalities to improve your English and above all to discover new cultures and have therefore a more rewarding Erasmus experience.