Imagine you’re in a Japanese class and your teacher is reading some vocabulary: “And the next word is “kyū-ryō,” which means ‘salary.’ Don’t get it confused with “kyō-ryū,’ which means “dinosaur.”

Unfortunately, you’re probably already confused.

And it wouldn’t be your fault! Research shows that learning similarly-sounding words is confusing. And words that sound similar and have similar meanings are even more confusing. (I’m looking at you, “Tuesday” and “Thursday.”)

But why is this confusing? And how should we teach vocabulary words that seem similar?

Why Similar Sounds Interfere with Memorization

We absorb new knowledge by connecting it to the knowledge that we already have. For example, if you already knew the word “kyū-ryō” (salary), then learning “kyō-ryū” (dinosaur) would not have been very difficult.

However, if both words are new to you, the connection between them prevents you from making connections to words that you already know.

So, when we’re introducing new words to students, it’s important to not introduce them to other words that look and sound similar. For example, we might be tempted to teach students a bunch of phrasal verbs involving the same verb (e.g. “hang out,” “hang up,” “hang tight”) or pairs of participle adjectives (e.g. “boring” and “bored”), but that’ll only make them harder to remember!

What about words that are related in meaning but don’t sound similar?

Words That Have Related Meanings

In language classes, we often teach related words together. This seems like an obvious choice. But does this actually help students?

It’s generally more effective for students to learn words in meaningful contexts than in lists of related words. Oxford’s How Vocabulary is Learned suggests letting adult students learn vocabulary as they encounter them.

That doesn’t mean we need to teach totally random words. After all, related words naturally occur within the same conversation or text. They just don’t occur in the way that typical vocabulary lists present them.

For example, if you try to think of words related to a library, you’d most likely think, “books,” “bookshelves,” “library card,” “reading,” “librarian.” They’re mostly nouns.

Yet, when we talk about a library in real life, we use a greater variety of words: “A boy who was reading a book in the library today couldn’t stop laughing. Everyone glared at him. Finally, the librarian said, ‘Quiet! This is a library!”

In this story, we’ve introduced the nouns (book, library, librarian), but also verbs (read, laugh, glare) and an adjective (quiet). Research has shown that teaching context-based words like these is more helpful than teaching random words or controlled lists of words.

But what do we do when we need to teach controlled lists of words?

What If We Need To Teach Related Words?

A study found that the word sets that people found difficult to remember often included names of objects that had similar shapes. When we learn new words, similarities in appearance interfere with our visual memory. So we’ll want to teach these words in separate contexts.

For example, we might struggle to remember the names of various small birds. But we won’t have trouble learning the name of a bird that is commonly found in parks (“pigeon”) along with other words related to parks (“bench,” “play,” and “fountain.”)

So we can teach each of these words in their own meaningful context. This applies even when we’re teaching simple words like “hot” and “cold.”

How Vocabulary is Learned suggests teaching such words "in sentences that help distinguish between their meanings.” So when teaching the word set, “hot + cold,” avoid sentences like:

• It is hot.
• He had a cold drink.
• I feel cold.

These sentences would still make sense if you switched the words: “It is cold,” “He had a hot drink,” and “I feel hot.” Instead, teach using sentences like:

• Summer is hot.
• Winter is cold.

📌 Takeaways

Congrats on getting to the end of this blog post! If you’re confused, it’s not your fault. We’ve just introduced a bunch of really similar information… sorry!

So to help you remember the key points, here they are again:

1. Don’t introduce words because they have similar sounds. For instance, if “strength” is a vocabulary word, don’t introduce “stretch” to the student as well.
2. In general, let context decide what words to teach.
3. When you need related words, teach them using meaningful context (“park” → “pigeon” “bench” “play” “water fountain”).

Happy tutoring!