Words represent abstract ideas. "Red" represents an arbitrary volume in RGB space. "Three" represents an abstraction. "Chair" represents an abstraction.
In all human languages the number of ideas is roughly the same (except for English, which has 450K curse words in addition). Foreigners learning English (I am one) struggle to learn the correct sequence of letters that produces the word in English corresponding to a particular abstraction. You struggle to learn the particular sequence of chicken scratch that represents the same abstraction in Chinese. Thousands of words in English, thousands of characters in Chinese, I fail to recognize any meaningful difference.
When I was learning English we were required to write each word 60 times in a row. We were learning between 50 and 120 new words every day. We were learning by heart short (one-page) texts in English which contained most of the new words for the day. As a result, we had a mechanical connection (writing) to the meaning of the word (repeating its meaning while you are writing it), and we also had it committed to memory in context. On top of that, we did weekly and monthly reviews of old words to refresh them in our memory, as well as compositions and translations to force us to apply them to new contexts.
Then I came to the US and realized that I couldn't speak the language. Write, read: yes; but speaking takes a whole new level of understanding. To get to that level you need full immersion. It takes about 3 months or more, depending on your non-speaking knowledge. Some Chinese students never learn plurals in English even after years in the US. Us foreigners will almost always mispronounce the sound "th", as in "there". Such is life.