One of the most common questions parents and therapists ask about AAC is deceptively simple: "When should I add more words?" The answer might surprise you. In most cases, the right time is sooner than you think.
Adding vocabulary to an AAC device is not like unlocking levels in a game. There is no magic threshold a child needs to hit before they "earn" access to more words. But there are real signs that tell you a child is ready for more, and there are practical ways to decide which words to add and when.
This guide walks through the signals, the strategies, and the common fears that hold people back from expanding vocabulary.
Signs It's Time to Add More Words
Every AAC user is different, but certain patterns show up consistently when a child is ready for more vocabulary. You don't need to see all of these at once. Even one or two of these signs can be a good reason to start thinking about new words.
1. They consistently use the words they already have
If a child is using their current vocabulary regularly and independently, that's a strong signal. Notice the word "consistently," not "perfectly." If the child reaches for "want" or "more" several times a day in the right contexts, they are showing you that they understand how AAC works and are ready for more tools.
2. They reach for things that aren't on the device
Watch what happens when a child wants something and can't find the right word. Do they point to a blank spot on the screen? Scroll around looking for something? Hand you the device with a frustrated expression? These are all signs that the child has something to say and doesn't have the vocabulary to say it.
3. They get frustrated during communication
Frustration during communication is not a sign to slow down. It is often a sign to speed up. When a child can't express what they need, adding relevant vocabulary gives them a way out of that frustration.
4. They start combining words
When a child goes from single words ("go") to two-word combinations ("go outside" or "want more"), they are showing you that their language is growing. Word combinations are a natural point to introduce new vocabulary that supports more complex sentences. Words like "and," "because," "not," or "but" can be powerful additions at this stage.
5. New activities or contexts come up
Life changes bring new communication needs. Starting at a new school, joining a sports team, getting a pet, visiting grandparents, celebrating holidays. Each of these introduces situations where the child needs words they might not have yet.
You Don't Need to Wait for Mastery
This is worth saying clearly: you do not need to wait until a child has "mastered" their current words before adding new ones.
Think about how spoken language works. When a baby is learning to talk, you don't stop using new words around them until they've perfected "mama" and "dada." You keep talking. You keep introducing vocabulary. You trust that exposure over time leads to learning.
The same principle applies to AAC. Research on aided language stimulation supports this approach. The people around the AAC user should be modeling a rich vocabulary, not restricting input to match the child's current output.
Banajee, DiCarlo, and Stricklin (2003) found that toddlers in natural settings use a small, consistent set of core words. But those toddlers were hearing thousands of words around them every day. The input was always far ahead of the output. AAC users deserve the same kind of language-rich environment.
The "Too Many Words" Fear
One of the biggest barriers to vocabulary expansion is the fear of overwhelming the child. Parents worry that adding too many words will confuse things. Therapists sometimes hold back because they want to make sure the child is "ready."
Here's the thing: there is very little evidence that having access to more words hurts communication. In fact, the research points in the opposite direction. Restricting vocabulary can limit a child's ability to express themselves and slow down language development.
Think about a speaking child's world. They are surrounded by thousands of words in books, conversations, TV, and everyday life. Nobody worries about "overwhelming" them with language. We trust that children take in what they're ready for and build on it gradually. Presuming competence means extending that same trust to AAC users.
That said, there is a difference between having words available and actively teaching them all at once. You can add 20 new words to a device without expecting the child to learn all 20 this week. The words are there when the child is ready for them. Focus your modeling and teaching on a few at a time, but don't lock the rest away.
Core Words vs. Fringe Words: What Should You Add?
When you decide to expand vocabulary, you'll need to think about whether to add core words or fringe words. The answer depends on where the child is in their AAC journey.
Adding more core words
Core words are the high-frequency, flexible words that show up in every conversation. Words like "want," "go," "help," "more," "not," "I," and "you." A small set of core words makes up the vast majority of daily communication.
If a child's device has a limited core vocabulary, this is almost always the best place to start. More core words means more flexibility. A child who has "want," "not," "go," "more," "help," and "like" can communicate across dozens of situations without needing topic-specific vocabulary.
Check out the core words list for AAC if you're looking for guidance on which core words to prioritize.
Adding more fringe words
Fringe words are the content-specific vocabulary that fills in the details. Names of people, places, foods, animals, toys, and activities. Fringe words are lower frequency individually, but they make communication personal and specific.
Fringe vocabulary is especially important when:
- The child has a solid core vocabulary but needs words for specific routines (meal choices, school subjects, family names)
- New activities or environments require new nouns and proper names
- The child is expressing interest in a specific topic (dinosaurs, a TV show, a sport)
For ideas on which fringe words to consider, see our guide on fringe vocabulary ideas.
The balance
A strong AAC system needs both. Core words give structure and flexibility. Fringe words give specificity and personal relevance. When in doubt, lean toward core words early on, then add fringe words as the child's world expands. The research consistently shows that core vocabulary matters for building flexible communication.
Practical Guidelines for Vocabulary Updates
How often should you review vocabulary?
There is no single right schedule, but here are some reasonable checkpoints:
- Weekly check-ins. Spend five minutes noticing what the child tried to say but couldn't. Jot down situations where they seemed stuck.
- Monthly reviews. Look at the overall vocabulary layout. Are there words the child never touches? Are there gaps in what they can express?
- Seasonal or life-event updates. Beginning of a new school year, holidays, family changes, new hobbies. These are natural times to add relevant fringe vocabulary.
- After any AAC assessment. If the child has had a formal evaluation, use the results to guide vocabulary decisions.
Our AAC timeline guide has more detail on what to expect at different stages.
Who should be involved in vocabulary selection?
The best vocabulary decisions come from a team, not one person making choices alone.
- The AAC user. Even if the child isn't verbally expressing preferences, pay attention to what they reach for, what they show interest in, and what makes them frustrated. Older children and teens should absolutely have a direct say in what goes on their device.
- Parents and caregivers. You know your child's daily routines, interests, and needs better than anyone. You see communication gaps that might not show up in a therapy session.
- Speech-language pathologists. SLPs bring expertise in language development and AAC systems. They can help identify which core words will have the biggest impact and suggest vocabulary organization strategies.
- Teachers and school staff. If the child uses AAC at school, teachers can identify vocabulary needed for classroom participation, social interactions, and academic content.
- Siblings and peers. Sometimes the best vocabulary ideas come from the people the child actually wants to talk to. What do siblings talk about? What do classmates discuss at lunch?
How to decide: add a word or wait?
Ask yourself these questions:
- Would this word help the child communicate in multiple situations? If yes, it's probably a core word and worth adding soon.
- Is the child showing interest or need related to this word? If they're reaching for something or getting frustrated, that's a clear signal.
- Does this word support a current goal or routine? Words tied to daily life get more practice naturally.
- Is this word motivating for the child? Sometimes the best word to add is the one the child actually wants to use, even if it seems less "important" from an adult perspective.
If the answer to any of these is yes, go ahead and add it. You can always adjust later.
Seasonal and Life-Event Vocabulary
One of the easiest ways to keep vocabulary fresh and relevant is to think about what's happening in the child's life right now.
School year transitions
- New teacher and classmate names
- Subject-specific vocabulary (art supplies, science terms, math words)
- School routine words (lunch, recess, bus, locker)
Holidays and celebrations
- Holiday-specific vocabulary (birthday, present, candle, costume, egg hunt)
- Family gathering words (grandma, uncle, cousin)
- Food words for holiday meals
Life events
- New sibling: baby, gentle, share, loud, quiet, hold
- New pet: the pet's name, feed, walk, gentle, outside
- Moving: new, house, room, miss, friend
- Starting a new activity: sport or hobby-specific vocabulary, coach/teacher name, equipment words
Seasonal interests
Kids' interests shift. A child who is obsessed with trucks in January might be all about butterflies by May. Keeping a few fringe vocabulary slots flexible lets you follow the child's lead.
How Many Words Should Be on the Device?
This is a question without a one-size-fits-all answer, but the general direction supported by research is: more is usually better than less. A robust AAC system gives the user access to hundreds or even thousands of words, organized in a way that makes them findable.
The key is organization, not restriction. A well-organized device with 500 words is easier to use than a cluttered device with 100 words thrown onto random pages. Good AAC apps (including SabiKo) use consistent layouts, logical categories, and motor planning principles to make large vocabularies manageable.
Common Mistakes to Avoid
Removing words the child doesn't seem to use. Just because a child hasn't used a word yet doesn't mean they won't. Keep vocabulary available. Think of it like books on a shelf. You don't throw away books a child hasn't read yet.
Only adding nouns. Nouns are the easiest vocabulary to think of, but core words like verbs, adjectives, and pronouns are what make real communication possible. "I want more" is a sentence. "Cookie" is a label.
Waiting for a professional's permission. Parents and caregivers can and should add vocabulary to a device. You don't need to wait for the next therapy session if your child needs a word today.
Adding vocabulary without modeling it. New words on the device are only useful if someone shows the child how to find and use them. Every time you add a word, commit to modeling it in natural conversations for the next few weeks.
The Bottom Line
Adding vocabulary to an AAC device is not something to be afraid of. It is one of the most impactful things you can do to support communication growth. Watch for the signs. Involve the right people. Lean on core words for flexibility and fringe words for relevance. And remember: you don't need perfection before progress.
The best time to add a new word is usually right now.
Want to get started with a vocabulary-rich AAC app? SabiKo gives your child access to core and fringe vocabulary in a clean, organized layout. Download it free on Google Play.