I was in my 30s when I learned "ennui" was pronounced "on wee" rather than N-U-I. I did not know it was from French. No shame. I never spoke the word aloud, but used it in writing. A teenager I knew was studying for a vocab test and had to learn the word, and I overheard him flash carding. Pronounced it "on-wee" and my brain exploded.
Copying lyrics from my favorite songs of the 80s was helpful. And then later on TV series and movies in english.
I've watched Friends, HIMYM and Californication* more than once (it's probably the reason I swear so much) and those really helped.
Now I raised my kid in english: from the beginning she was only ever allowed to watch TV shows in english. And she's always been to international schools, in english too.
The other day she taught me a simply word which, surprisingly enough, I didn't know: a "coaster" (a drink coaster).
My absolute favorite is when she uses english grammar and applies it to french: the rules about where adjectives do go vary between french and english and she regularly messes it up in french (supposedly her "native" language but at this point I wonder whether english ain't a first language, and french second).
And one thing she has that I'll never have is a beautiful, proper, english accent. Mine shall forever be a strong french one.
A French accent in English is easy to mock but it actually sounds pretty good. My American accent in Spanish sounds atrocious and sadly our bilingual kids have pretty American accents too. But honestly who cares?
Speaking another language is the best effort I have ever made (I am lucky not to do it out of necessity). Totally changed my world view and how I think, speak, read and dream. Though please do not make me listen to a recording of my own voice…