The clearest sign your child may need speech therapy is falling behind specific communication milestones for their age. No babbling by 9 months, no words by 15 months, no two-word combinations by 24 months, or speech that strangers can’t understand by age 3 are all reasons to seek an evaluation. Beyond these benchmarks, there are subtler signs worth knowing about, because early intervention consistently leads to better outcomes.
Age-by-Age Red Flags
Children develop at different rates, but certain milestones have fairly firm timelines. When a child misses them, it doesn’t guarantee a disorder, but it does mean an evaluation is worthwhile. Here’s what to watch for:
- By 9 months: No babbling at all. Babies should be stringing consonant-vowel sounds together (“ba-ba,” “da-da”) even without meaning behind them.
- By 15 months: No first words. Even one or two consistent words (including “mama” or “dada” used with intent) counts.
- By 18 months: No consistent words. A child this age should be using a handful of words regularly, not just occasionally.
- By 24 months: No word combinations (“more milk,” “daddy go”) or speech that even you, the parent, struggle to understand.
- By 36 months: Strangers have trouble understanding your child’s speech, or your child isn’t speaking clearly enough to communicate basic needs to unfamiliar people.
- By kindergarten age (5 to 6): Difficulty learning colors, numbers, shapes, or the alphabet, which can signal underlying language or memory issues.
Two patterns deserve immediate attention at any age: a sudden loss of speech or language skills, and a child who shows no interest in communicating at all. A child who was saying words and stops, or who doesn’t attempt to get your attention through gestures, sounds, or eye contact, should be evaluated promptly.
Speech Problems vs. Language Problems
Parents often use “speech” as a catch-all, but clinicians distinguish between two different issues that can occur separately or together. Understanding the difference helps you describe what you’re seeing to a pediatrician or therapist.
A speech disorder involves the physical production of sounds. Your child might have ideas and sentences ready but struggle to pronounce words clearly. Think of a 4-year-old who says “wabbit” instead of “rabbit” or leaves off the beginnings of words. The mouth, tongue, lips, or vocal cords aren’t coordinating the way they need to. A child with a speech disorder can have perfectly normal understanding and vocabulary.
A language disorder is about the underlying system of communication. A child with an expressive language disorder has trouble putting thoughts into words, forming sentences, or finding the right vocabulary. A child with a receptive language disorder has trouble understanding what others say to them. You might notice they don’t follow directions well, seem confused by questions, or can’t retell a simple story. Their pronunciation might be perfectly clear, yet the content or comprehension lags behind.
Some children have both. A child who is hard to understand and also seems to struggle with following conversations may have overlapping speech and language difficulties. Knowing which type your child has shapes the kind of therapy they’ll receive.
When Mispronunciation Is Normal
Not every sound substitution is a problem. Children master different speech sounds on a predictable schedule, and expecting a 3-year-old to say “r” correctly is like expecting a toddler to ride a bike. Sounds like /s/ and /l/ are typically mastered around age 4 to just before age 5. The /r/ sound, along with “th” (as in “thin” and “this”), often doesn’t solidify until ages 5 through 6, sometimes closer to 7.
These timelines are based on when 90% of English-speaking children can produce the sound correctly in words. The normal range has a spread of 6 to 18 months depending on the sound, so there’s plenty of room for individual variation. If your child is substituting sounds that are age-appropriate to still be developing, that’s usually not a concern. If they’re missing sounds that most peers mastered a year or more ago, or if the errors make them very hard to understand, that’s worth investigating.
Stuttering: Normal Phase or Real Concern?
Many children go through a phase of disfluent speech between ages 2 and 5. They repeat whole words (“I-I-I want that”), use filler words, or restart sentences. This is typical and usually resolves on its own.
Stuttering that may need professional attention looks different. Watch for repetitions of individual sounds or syllables rather than whole words (“b-b-b-ball” instead of “I-I-I want”), stretching sounds out longer than normal (“Sssssometimes we go”), silent blocks where your child’s mouth is in position but no sound comes out, and visible physical tension or struggle in the face or neck while trying to speak. The frequency and severity of these moments often fluctuate from day to day and across different situations.
If your child starts avoiding speaking, seems frustrated or embarrassed by their stuttering, or develops secondary behaviors like blinking or head movements while trying to get words out, those are signs the stuttering is affecting them beyond just the speech itself. A speech-language pathologist can determine whether the pattern is likely to resolve or whether therapy would help.
Social Communication Difficulties
Some children speak clearly and have a solid vocabulary but struggle with the social side of language. This is sometimes called pragmatic language, and it covers skills like starting and maintaining a conversation, taking turns in dialogue, adjusting how you talk depending on who you’re speaking to, reading body language and facial expressions, and staying on topic.
A child with pragmatic difficulties might talk at length about their own interests without noticing the other person has lost interest, stand too close during conversation, interpret figures of speech literally, or have trouble understanding jokes. These issues can show up more clearly once a child enters school and the social demands of the classroom increase. Pragmatic language difficulties are sometimes associated with autism spectrum disorder, but they can also occur on their own.
Physical Signs to Watch For
Some speech difficulties have a physical component that’s easy to overlook. Excessive drooling past toddlerhood, difficulty sucking, chewing, or swallowing, and poor coordination of the lips, tongue, and jaw can all affect speech development. These signs suggest the muscles involved in speech production may need strengthening or retraining, which a speech-language pathologist can address directly.
Tongue-tie (a tight band of tissue under the tongue that restricts movement) is another physical factor parents often ask about. The evidence on its effect on speech is mixed. Some studies show children with untreated tongue-tie make more articulation errors than those who’ve had it corrected, but other research finds no significant difference in word- and sentence-level clarity. If your child has a visible tongue-tie and is also struggling with specific sounds that require tongue elevation, it’s reasonable to have both an ENT and a speech-language pathologist weigh in.
Hearing is the other physical factor that’s easy to miss. A child who doesn’t respond when spoken to, doesn’t react to loud noises, or seems inconsistent in their attention to speech may have hearing loss affecting their language development. Even mild or intermittent hearing loss from chronic ear infections can delay speech. A hearing evaluation is typically one of the first steps in any speech-language assessment.
Bilingual Children and Delayed Speech
If your child is growing up with two languages, their development in each individual language will look different from a monolingual child’s. Bilingual children typically lag behind monolingual peers when you measure just one of their languages in isolation. This is expected and not a sign of a disorder. Their total vocabulary across both languages grows at the same rate as, or faster than, a monolingual child’s total vocabulary.
Grammar development in each language may take longer, with some research suggesting bilingual children catch up to monolingual peers by around age 10 under consistent exposure to both languages. The key distinction: a true language disorder shows up in both languages, not just one. If your child is behind only in English but developing normally in your home language, that’s a bilingual acquisition pattern, not a delay. If they’re behind in both, an evaluation is appropriate. One common problem is that bilingual children get tested only in English using norms designed for monolingual English speakers, which can make normal bilingual development look like a deficit.
What Happens During an Evaluation
If you decide to pursue an evaluation, knowing what to expect can make the process less stressful. A comprehensive speech-language assessment typically includes a detailed case history covering your child’s medical background, developmental milestones, and the languages spoken at home. The evaluator will interview you about your concerns and may also talk with your child’s teacher to understand how they communicate in the classroom.
Your child will be observed during play or structured activities, and the evaluator will use a combination of standardized tests and informal measures to assess their skills. For very young children or those who can’t sit through formal testing, the evaluator relies more on observation and criterion-based benchmarks. For example, a 3-year-old is expected to use 50 or more different words, and falling well short of that standard is one way delays are identified without needing a formal test score.
For older children, standardized tests produce scores that are compared to what’s typical for their age. A score falling more than two standard deviations below average is considered severely low, something only about 2% of children would score. The evaluator also uses clinical judgment, your input, and classroom observations to build a full picture rather than relying on a single test number.
How to Get Started
You don’t need a referral from your pediatrician to have your child evaluated, though your pediatrician can be a helpful starting point. In the United States, children under age 3 can be evaluated for free through your state’s Early Intervention program under Part C of the Individuals with Disabilities Education Act. Each state sets its own eligibility criteria for what counts as a significant enough delay to qualify for services, but the evaluation itself is available to any family with concerns. For children ages 3 and older, your local school district is required to evaluate your child at no cost if you request it in writing, regardless of whether they attend that school.
You can also go directly to a private speech-language pathologist. Many are covered by insurance, especially with a referral. The evaluation typically takes one to two sessions and results in a clear picture of where your child stands, whether therapy is recommended, and what specific goals would be targeted. If your gut tells you something is off, requesting an evaluation is never premature. The downside of waiting is real; the downside of evaluating a child who turns out to be fine is essentially zero.