Imagine you're learning the English names of different fruits.
Your vocabulary list looks like this:
peach, pear, plum, apricot, fig
All five words belong to the same category. They're easy to organize, and the list looks perfectly sensible.
But a few minutes later, someone asks you to remember the English word for a particular fruit.
Was it peach or pear? Was plum the one you were thinking of?
The words seemed easy to understand while you were studying them together. Remembering the right one is another matter.
Now imagine a different vocabulary list:
check in, boarding pass, gate, delayed, take off
These expressions don't all belong to the same grammatical or meaning category. Some describe actions, others describe objects or situations.
Yet they fit naturally into the same experience: taking a flight.
You might use several of them during a single trip.
Both lists have a clear organizing principle. But they create different kinds of connections between the things you're learning.
And according to vocabulary research, the way we group new words can influence how easily we learn and remember them.
1. Why learning words by category seems so natural
If you open a beginner's English textbook, you'll probably find chapters called Food, Colors, Animals, Clothes, and Parts of the Body.
There's a good reason for that.
Categories help us organize information. They're familiar, easy to understand, and useful for finding words related to a particular subject.
If you want to describe what someone is wearing, learning clothing vocabulary makes sense. If you're trying to understand a recipe, knowing the names of common ingredients is helpful.
But there's a difference between organizing vocabulary you already know and learning several unfamiliar words at the same time.
When you're reviewing known vocabulary, a category can help you bring related words to mind.
When nearly every word is new, those similarities may sometimes work against you.
Consider four kitchen items:
cup, mug, glass, bowl
They share several characteristics. They're objects found in kitchens, and many can hold food or drinks.
These connections make the words easy to group together. But they can also make it harder to remember which unfamiliar label belongs to which object.
You need to learn not only that all four belong to the same general area, but also how each one differs from the others.
And when you're just beginning, that additional competition can matter.
2. When similar words get in each other's way
Researchers have a name for grouping words that share a meaning category: semantic clustering.
For example:
- Animals: cat, dog, rabbit, horse
- Colors: red, blue, green, yellow
- Furniture: desk, table, chair, stool
The words in each group belong to the same general category. They're also often the same kind of word grammatically, such as nouns or adjectives.
In a 1993 study, researcher Thomas Tinkham investigated whether learners acquired unfamiliar foreign-language words more easily when those words were semantically related.
His experiments suggested that learning new words in closely related groups was more difficult than learning unrelated words.
Robert Waring conducted a replication study in 1997 and found a similar disadvantage.
One possible explanation is interference.
When several new words have similar meanings, remembering one may activate competing words from the same group.
Imagine trying to recall stool, but chair keeps coming to mind.
You understand the general category. You just haven't formed a sufficiently strong connection between each particular word and its meaning.
This doesn't mean the words are impossible to learn together. It means that their similarity can introduce an additional challenge.
And this effect isn't limited to older research.
A 2022 study by Pérez-Serrano, Nogueroles-López, and Duñabeitia examined vocabulary learned incidentally through video. Participants generally recalled and recognized unfamiliar labels better when they were presented alongside semantically unrelated items.
Together, these studies raise a useful question about a familiar teaching practice.
Just because words belong together in a dictionary or textbook doesn't necessarily mean they're easiest to learn together.
3. But newer research tells a more complicated story
Before abandoning your vocabulary categories, there's an important development worth knowing about.
In 2026, researchers Muhang Li, Takumi Uchihara, Tatsuya Nakata, and Victoria Murphy published a large meta-analysis of research on semantic clustering.
Rather than examining a single experiment, they brought together results from numerous studies investigating how grouping similar words affects vocabulary learning.
Their findings were more nuanced than the simple claim that semantic categories make learning worse.
The analysis found that learners generally needed more attempts to learn semantically related words during initial practice.
However, this disadvantage did not translate into a significant overall difference in the immediate vocabulary tests administered after learning.
The researchers also found that factors such as longer training sessions and providing meaningful context could influence the results, sometimes making semantic grouping beneficial.
In other words, closely related vocabulary may be more demanding at first without necessarily producing worse learning outcomes.
That's an important distinction.
A method that takes more effort during the first few minutes isn't automatically a bad method. And a method that feels easy immediately isn't necessarily the best for every learning goal.
The research doesn't establish one universally superior way to organize vocabulary.
Instead, it suggests that word grouping interacts with how we practise and what we're trying to learn.
So rather than asking whether categories are good or bad, we should ask when they're useful.
4. What changes when words belong to the same situation?
There's another way to organize vocabulary: connect words through a shared event, activity, or situation.
Researchers often call this thematic clustering.
Instead of grouping words because they have similar meanings, we group them because they're likely to appear together in a meaningful context.
Think about visiting a café.
You might need:
a table for two
"Could we have a table for two?"
I'd like...
"I'd like a coffee, please."
for here or to go
"Is that for here or to go?"
the check
"Could we get the check, please?"
pay by card
"Can I pay by card?"
These expressions aren't all members of one semantic category.
They do different jobs. One helps you ask for a table. Another helps you order. Another concerns paying.
But together, they support a recognizable sequence of events.
This can make the vocabulary easier to relate to a practical goal: managing a conversation at a café.
In a 1997 study, Tinkham compared semantic grouping with thematic grouping. While closely related semantic groups were harder to learn, thematically connected words showed an advantage over unrelated groups in his experiments.
That doesn't prove that every situation-based vocabulary set is better than every category-based set.
A classroom experiment with selected words is not the same thing as a complete learning program.
And a situation-based set can still contain confusing or overly difficult vocabulary.
But the findings suggest a useful principle: words can be meaningfully connected without competing to express nearly the same thing.
A well-designed situation can give each expression a distinct purpose.
5. Categories tell you what words are. Situations show you what to do with them.
Consider the difference between these two vocabulary sets.
One is called Food.
It contains names of ingredients, dishes, and drinks.
The other is called Ordering at a Restaurant.
It contains expressions for asking about the menu, ordering, making a request, and paying.
Neither set is inherently better.
They simply answer different questions.
The first helps you identify and describe things.
The second helps you accomplish something.
That's a useful distinction when deciding what to learn.
If you're a beginner who wants to recognize common foods in English, a food vocabulary set may be exactly what you need.
If you're preparing to visit an English-speaking country and want to feel comfortable ordering a meal, a situation-based set may be more immediately useful.
And if you already know most of the food words, you can combine the two:
"I'd like the chicken with rice, please."
The words you know become part of a practical expression.
This is one reason vocabulary shouldn't be thought of as a collection of isolated labels.
Words help us describe things, but they also help us ask, explain, request, respond, and communicate.
A useful vocabulary collection can support either goal — or both.
6. When categories are still the right choice
Let's return to those familiar beginner topics: colors, animals, clothes, and food.
Should we stop learning them as groups?
No.
In fact, there are several situations where category-based learning makes excellent sense.
When many of the words are already familiar
Suppose you already know red, blue, green, and yellow.
Reviewing these words together probably creates much less difficulty than trying to memorize four completely unfamiliar labels.
You're strengthening existing knowledge rather than establishing every connection from scratch.
A category can also help you notice which words you still don't know.
When you need to understand the differences
Sometimes the whole purpose of an exercise is to distinguish similar words.
For instance:
borrow and lend
Both involve temporarily transferring something between people, but from different perspectives.
"Can I borrow your pen?"
"Can you lend me your pen?"
Studying these words together can be useful because you're deliberately comparing their meanings and usage.
The key is that you're doing more than memorizing two similar translations. You're learning what makes them different.
When a category matches your immediate goal
If you want to describe the rooms in your home, learning furniture vocabulary is sensible.
If you want to talk about your health, learning common body parts can help.
A meaningful learning goal is a perfectly good reason to use a category.
The research on interference doesn't make these collections useless. It simply suggests that introducing too many closely related unfamiliar words at once may demand extra care.
You can start with a few important items, add more over time, and use clear examples to distinguish them.
7. How to choose a useful vocabulary set
You don't need to understand research terminology to apply these ideas.
Before starting or creating a vocabulary collection, ask yourself what you want to achieve.
If you want to learn the names of things
A category-based set is a natural choice.
Examples include common foods, household objects, clothing, or colors.
If many words are new and very similar, consider learning a smaller selection first rather than attempting the entire category in one session.
If you want to handle a real-life situation
Choose vocabulary that helps you move through that situation.
For example, At the Doctor's Office might include:
- make an appointment — "I'd like to make an appointment."
- I've been feeling... — "I've been feeling dizzy."
- It hurts when... — "It hurts when I move my arm."
- prescription — "Do I need a prescription?"
- follow-up appointment — "Should I schedule a follow-up appointment?"
These expressions are connected by what happens during a visit, not because they all mean similar things.
The result is a collection you can imagine using.
If you often confuse similar words
Practise their differences explicitly.
Use short example sentences that make the meaning of each word clear.
For example:
"I put the cup on the table."
"I poured the water into a glass."
You can also compare the words directly once you have a basic understanding of them.
The goal is not to avoid related words forever, but to develop reliable distinctions between them.
If you're reviewing familiar vocabulary
Choose whichever organization makes the review useful or enjoyable.
You might revisit a food list, practise expressions for a hotel stay, or listen to a collection of common verbs.
At this stage, variety in how you use the words may matter more than keeping every collection perfectly organized.
And if you enjoy a particular topic, that's a valid reason to study it. A collection you actually return to is more useful than a theoretically ideal one you never open.
8. A useful vocabulary set doesn't need one rigid formula
It's tempting to turn research findings into strict instructions.
Never teach similar words together.
Always organize vocabulary by situation.
Avoid lists of colors and animals.
But those rules would go further than the evidence supports.
A useful vocabulary set depends on several things: how familiar the words are, how easily they can be confused, whether the examples explain their meanings, and what the learner wants to accomplish.
This is especially relevant for short vocabulary sessions.
A collection of 20 or 25 cards might contain single words, common expressions, and short phrases. Each card can include a natural example sentence that gives the item a little more meaning.
In Vocafy, Voca sets follow this general approach: a word or expression together with an example that can be read and listened to.
Some sets naturally focus on categories. Others follow situations, communicative goals, or commonly used expressions.
That flexibility matters because learners don't always have the same needs.
One person wants to recognize the ingredients in a recipe. Another wants to understand announcements at an airport. Someone else needs a few reliable expressions for a meeting at work.
Forcing all three into the same kind of vocabulary collection wouldn't make much sense.
What matters is that the words belong together for a useful reason — and that the set doesn't introduce unnecessary confusion.
So, should you learn words by category or by situation?
The answer isn't that one method wins and the other loses.
Categories help organize related meanings. Situations connect language to things we want to understand or do.
Research suggests that learning many similar new words together can create interference, particularly during early practice.
But the latest evidence also shows that this doesn't necessarily lead to worse final learning results, and that meaningful context can make a difference.
So keep your useful categories. Learn the names of foods, colors, objects, and anything else that interests you.
Just don't assume that every group of similar words is automatically the easiest group to learn.
And when your goal is communication, think beyond the category.
Instead of only asking, "What words belong to this topic?", try asking:
"What would I actually need to understand or say in this situation?"
That small change can lead to a different kind of vocabulary collection.
One that doesn't just help you remember what words mean, but gives you a clearer idea of when and why you might use them.
