Steve Kaufmann is an undisputed celebrity in the language study community. According to Wikipedia, "[a]s of 2023, he has an understanding of 20 languages, to varying degrees". In his blog, he says "Vocabulary is much more important than grammar. The grammar you acquire gradually as you become familiar with the language, with the words, but first of all you need words." This caused much debate in the Facebook "Polyglots (The Community)" group. Most comments disagree with him. To find out whether this disagreement is genuine, I started a poll in the same group.
"For all the languages you're studying, given 10 hours dedicated to vocabulary and grammar, what is the average ratio of time of your study in these two areas? It's true that oftentimes there is overlap. What is polled here is a subjective one. So just give a rough estimate."
After a few days, there are 42 votes. The following is the result, shown as ratio of vocabulary:grammar study time, and percent of the responses
8:2 30%
9:1 20%
10:0 15%
7:3 11%
5:5 9%
4:6 8%
1:9, 3:7, 6:4 2%
2:8 1%
We can see that for instance nearly 1/3 of the language learners spend 8 out of 10 hours studying vocabulary and 2 hours studying grammar, while 1% of the people do exactly the opposite. This result shows that the polyglots taking this poll definitely spend more time studying vocabulary than grammar. If this time distribution implies relative importance, it is clearly consistent with Mr. Kaufmann's opinion that vocabulary is more important than grammar.
This poll is followed by 26 comments. Some interesting findings from them are:
(1) If the learner is a beginner in learning a specific language, he or she spends a significant amount of time studying grammar. The vocabulary:grammar study time ratio could be 5:5 or even lower. But as study progresses, the ratio gradually increases.
(2) This poll is about the learner's current state, averaged over all the languages being studied if multiple. One interesting example is a Portuguese learner who says 10:0 when studying Spanish (no need to study grammar as the two languages are so much alike on that), 8:2 when studying English, and 7:3 when studying Swedish. So I did an average for him, which is (10+8+7):(0+2+3)=25:5=8.33:1.67 or about 8:2. He agreed.
(3) Different languages require different ratios. For example, Chinese is generally considered to demand an extraordinary amount of time on vocabulary but very little time on grammar, unlike say Latin, Ancient Greek, or Sanskrit. Since many languages are studied and polled about, there won't be bias introduced by any specific language. And if a learner is studying multiple languages, he's supposed to enter his average.
(4) Some people say they don't study either because their study is completely immersion. That is unusual for an adult learner. But lack of urgency, prioritizing fun well above everything else, and having a childlike curious mind make this option possible.
Back to Kaufmann. We can reasonably believe that he is at an advanced stage on all or most of the languages he knows. As said above (see (1)), at this stage, the vocabulary:grammar ratio tends to be high, leading him to make that remark. Why do people show their disagreement with him? It's possible that most people have the tendency to misread "X is more important than Y" as "X is important but Y is not". This tendency is especially common when people read an online article about health or medical science. Secondly, people disagree with somebody else by interpreting the latter's words as a universal rule, to make it more criticizable. If one of the languages you're studying takes more time on grammar than vocabulary, even if you're studying multiple languages for which this ratio is averaged to be in favor of vocabulary instead, you still disagree by ignoring the average.