[grepherder]

100 words per day is definitely possible with very clever techniques and hard work, so is a vocabulary of about 20,000 words in 5 months, but to be fluent (C1) in using them is another story. It is certainly unrealistic unless we're talking 8+ hours a day immersion.

[shin_lao]

I think you may plateau quickly with 100 words per day and I think that plateau is well below 20,000 words.

Memorizing a foreign language word is not just translation, it's about understanding context and usage for that word.

When you tread outside the "trivial vocabulary kit" you lose bijection between languages and acquiring words becomes harder and harder.

Keep in mind I have nothing but my personal experience to back that up, which means formal studies on the topic are more than welcome to enrich the conversation.

[grepherder]

>> Memorizing a foreign language word is not just translation, it's about understanding context and usage for that word.

Exactly. I didn't mean to suggest that you can actually "learn" those 100 words in a meaningful way. That treshold is also difficult to measure indeed, I also can't back that up besides anecdote without spending some time looking into research. Anyway, my point wasn't that at all. I was actually trying to state it's not realistic to assume a 100 word per day acquisition, because that would mean you would spend 4-5+ hours a day _just_ to know certain translations of those words, without any context or very little if any. I'm talking about something very mechanic that would gain you very little in real language acquisition terms for the effort you spend. Unrealistic scenario unless you're trying to win a bet.

Also, it's worth to note that this depends strongly on how you actually define new words, i.e. what kind of inflections etc. you consider to be distinct words. In languages where you can derive an average of 3-4 new words for every word you learn this can become almost trivial.