You Can Use Grammar Without Knowing the Rules: What a Subtle Uneasiness in Japanese Taught Me

The other day, while writing a blog post in Japanese, I came across a sentence that did not feel quite right.

It roughly meant, “There was also a competition at which robots demonstrated martial arts-like movements.” In the Japanese sentence, however, I had used the past-tense form of “demonstrate” inside the clause describing the competition.

Something was off.

So I changed that verb from the past form, shita, to the non-past form, suru.

Yes. That sounded right.

But then an odd question occurred to me.

Why should it be suru rather than shita?

The competition took place in the past, so it seemed as though the past form should also work for the robots’ demonstration.

Yet my instinct as a native Japanese speaker told me that suru was more natural.

I did not know why.

I assumed there was an explanation in a Japanese grammar book somewhere. I decided to ask AI later.

I Asked AI

According to AI, the tense of a clause modifying a noun in Japanese does not necessarily have to match the tense of the sentence as a whole.

“The competition was held” describes a past event, while “robots demonstrate movements” explains the content or nature of that competition.

In other words, “a competition in which robots demonstrate movements” works as a single descriptive unit, and the final verb, “was held,” places the event in the past.

The version with the past form, “demonstrated,” is not necessarily ungrammatical. It simply draws more attention to the completion of the demonstration and gives the sentence a slightly different nuance.

I see. So that is how it works.

…Actually, I still do not entirely understand it. (laughs)

The explanation sounds convincing when I read it, but I am not confident that I will remember the logic and apply it the next time I write a similar sentence.

After all, I corrected the sentence without knowing the grammatical rule in the first place.

Apparently, after using Japanese for more than 50 years, I have learned to sense when something is wrong even if I cannot explain why.

Can Native Speakers Explain Grammar?

This reminded me of my own experience studying English.

As an English learner, I often get caught up in small points of grammar.

Why is the past subjunctive used here? Why is this plural rather than singular? Why this preposition?

Each time, I look up the grammatical explanation.

But what would happen if I asked a native English speaker the same questions?

“That is just how we say it.”

It would not be surprising to receive an answer like that.

If a sentence were clearly wrong, a native speaker could immediately say, “We would never put it that way.”

But what about a sentence that seems grammatically possible and still sounds slightly unnatural?

Even a native speaker might struggle if asked to explain the difference in grammatical terms.

In fact, I once heard a story about something like this.

In an English class, a student asked the native-speaking teacher about the difference between the relative adverb where and the relative pronoun which.

“Why can’t we use which in this example?”

The teacher was at a loss for an answer.

In the end, another student opened an English grammar reference book and explained it.

Being able to speak English as a first language and being able to teach English grammar are two different skills.

Come to think of it, if someone asked me to teach Japanese, I would probably be in trouble from day one.

Knowing Grammar and Being Able to Use It Are Not the Same

Grammar is often said to be important when learning a foreign language.

I agree.

But understanding grammar does not mean that you can use it naturally.

My Japanese sentence was a perfect example.

I did not know the rule. Even so, I sensed that something was wrong and corrected the sentence so that it sounded natural.

That ability probably came from spending many years reading, hearing, speaking, and writing Japanese.

The same should be true of English.

Understanding the rules in a grammar book is only the starting point.

From there, you need to encounter a huge amount of English, use it yourself, make mistakes, and correct them. Through that repetition, you gradually develop the ability to feel that something is somehow not quite right.

There is a considerable distance between understanding a rule intellectually and being able to choose the right expression in an instant.

In the end, I think the only thing that can close that gap is practice.

“It Just Feels Right” May Be the Final Destination

When I study English, not knowing the grammatical reason behind something bothers me, so I tend to look it up.

Ultimately, however, the goal may be to choose natural expressions without consciously thinking about grammar every time.

Just as I did with that Japanese sentence.

“Why is this version correct?”

“I don’t know. It just sounds more natural.”

If I ever become able to give that answer in English, it may be a sign that I have made considerable progress.

Of course, by the time I reach that point, I may no longer be able to explain the grammar to Japanese learners who ask me about it.

After years of study, I may finally achieve the native-like ability to say, “It just feels right.”

Language learning is a remarkably long way around.