Ask HN: I’m already fluent in English. How can I improve further?

I was born in one, lived long in a second and now am home in a third country.

In all three languages I feel confident, can tell jokes, understand and have tested level C2 (https://www.efset.org/cefr/).

Still, every once in a while, I "have this feeling" my proficiency is subpar. Still I learn new expressions and grammar twists that I was now aware about before.

What helps me getting more certain and better in the word craft of the local language is asking locals to correct me and ask them to explain words and constructs that seem strange or unknown to me.

My mother told me that watching TV in English made a big impact on her English fluency.

Knowing which preposition to use is sometimes challenging.

Prepositions are one of the hardest things to translate. Sometimes, translating it one way gives it a different meaning than you intended and other times it really doesn't but wouldn't be the "common" usage.

To give an example, my sister was going on about people translating stuff in the Harry Potter books, looking for hidden meanings, and she told me Voldemort was French for "flight of death" and I told her "No, de can also be translated as from. I would translate that flight from death."

Flight of death is nonsense in English. It doesn't make sense. Flight from death has a completely different meaning and makes perfect sense -- Lord Voldemort was trying to get out of dying. He was trying to escape his own death. He was fleeing from death.

But if you are talking about someone's hometown, saying "Doreen, from Columbus" or "Doreen, of Columbus" means the same thing and most people wouldn't misunderstand it. De in French is often used that way as well and it more or less doesn't matter which of the two English prepositions you use.

Yes, but then it is something like reading those list of acronyms definitions where LOL somehow means "hail Satan" (urban dictionary often is quite good, but in the context of the question this can be a serious problem). I would recommend it more for refreshing old memories rather than for learning.

The answer to your question really depends on what you need it for. Technical or content writing? Work communication? Deeper conversations in your personal life?

I think the most broadly applicable answer is to read the most famous English stylists such as Gibbon, Carlyle, Arnold, or novelists like Austen, Eliot, Henry James, etc. This writing is complex and sophisticated enough to be challenging even to native speakers, but the vocabulary is still almost totally congruent with modern English.

However, since you're posting on HN, I suspect you'd like a response from a more technical perspective, in which case my answer is: read and write open source documentation! Writing good docs requires complete understanding of the terminology and concepts involved, as well as compositional skill and precision. It's a great exercise which will improve your English, as well as your understanding of the code you're writing about - and as a bonus you're giving something back while you learn.

> I’m also aware of my grammar not being perfect.

As a native English speaker is this funny since English grammar is a bit fluid.

> Knowing which preposition to use is sometimes challenging.

True that. Also adjective order.

My suggestion is read and watch popular English fiction. I say that because I'm dubious that your English is technically deficient. More likely has to do with the intersection of culture and language. As in when and how to shift from formal to informal depending on situation. Also remember the English speaking world itself is fragmented. For instance I can often tell where someone grew up in the Bay Area by their speaking style.