According to research, 1000 most common words in a foreign language account for 75% - 80% of understanding of a daily conversation.
A short paragraph from our article "Best way to learn a language: Learn 1000 words" citing the research:
"Professor Webb, who has studied language learning at the University of Western Ontario says for BBC “the most effective way to be able to speak a language quickly is to pick the 800 to 1,000 lemmas which appear most frequently in a language, and learn those."
The whole article with research and references here:
https://vocabulary-miner.com/best-way-to-learn-a-language/What do you think about it?