This is the kind of sentiment I had when people ask me about 日本語 regarding: “do Japanese people memorize all 50000+ Kanji?” I’m like “NO” since they don’t know all characters as only a small percentage of that is taught & used, around 2136. Although, some people learn jargon catered to specific fields (science, medicine) leading to them knowing 3000+ Kanji.
The estimated count for the “number of words” in English is 1,000,000 but that’s not an exact answer. The thing is, how many words is a native English speaker expected to know & understand? How much vocab do they teach students at school (from spelling to grammar)? After learning the alphabet, what types of words are taught across schools in the Anglosphere to kids?
For perspective, kids in Japan only learn 80 Kanji in their first year (mainly common & easy ones: 犬、校、九、女、男、名、森、右 to list a few) but the number expands through their years. I mean, something “similar” exists in English with spelling being taught at schools (teachers give a list of words to memorize spelling followed by a spelling test later).
The vocab lists expand from elementary to high school with difficult words (there’s a difference in difficulty with trying to spell a word like “animal” to “conscientious”). It’s like how a Japanese kid knows how to handwrite 海外 but has a hard time on trying to understand 傭兵 (ようへい) since 傭 is a harder Kanji to write in comparison to 海.
Not exactly what you are asking, but there have been several intentionally developed lists of words to help non-English speakers learn English, including BASIC English and Learning English. Most of these vocabulary lists are generally under 2,000 words, but over 1,000 words. Knowing these words, it is generally considered that you can start to have a discussion in English, either with a native speaker or with someone who also only knows these words.
I think that one thing which trips up a lot of alphabet based learners is that I can feel pretty close to knowing what a word sounds like by reading it even if I don’t know what the word means. I don’t know how I could do that in a logographic language.
The difference between the systems can be summed up as:
English: read more words than they can speak.
Japanese: speak more words than they can write.
A native english speaker might use less than 15,000 words in common conversation. That same speaker in written communication can use 30,000 words and comprehend over 100,000 when reading.
In Japanese and other logographic languages, the verbal vocabulary is usually greater than the written one. A complete reversal of the pattern.
For Japanese at least, there’s 訓読み & 音読み in which the Kunyomi reading is the native Japanese way of pronouncing the Kanji while Onyomi is the pronunciation derivative from Mandarin, i.e. 戦う for “to fight” is read as たたかう via Kunyomi while 戦争 (“war”) is read as せんそう bearing the Onyomi reading.