What Are the 3 Types of Stuttering? Repetitions, Prolongations & Blocks
Stuttering is a difference in the flow of speech that can make it difficult to get words out smoothly. A person who stutters may repeat sounds or words, stretch out sounds, or experience moments when speech seems to stop temporarily.
When people talk about the “3 types of stuttering,” they are usually referring to three common stuttering behaviors: repetitions, prolongations, and blocks. These are different ways that stuttering can interrupt the flow of speech—they are not three separate diagnoses.
Stuttering can look and sound different from person to person. Some people may primarily experience repetitions, while others may experience a combination of repetitions, prolongations, and blocks. The frequency and severity can also change depending on the situation.
If you're concerned about your child's speech, learning to recognize these different behaviors can help you understand what they may be experiencing and when it may be helpful to consult a speech-language pathologist (SLP).
What Is Stuttering?
Stuttering is a fluency disorder that affects the flow or timing of speech. It can involve interruptions in speech that make it difficult to say a word or express a thought as intended.
Common characteristics of stuttering include:
Repeating sounds, syllables, or words
Holding a sound for longer than expected
Getting temporarily "stuck" on a sound or word
Physical tension during moments of stuttering
Avoiding certain words or speaking situations
Using extra movements or behaviors to try to get through a difficult moment
Everyone is disfluent sometimes. People may pause, say “um,” repeat a word while thinking, or change what they were going to say. These everyday disruptions don't necessarily mean that someone stutters.
The difference is that stuttering involves particular patterns of speech disruption and can sometimes have a significant impact on communication and a person's experience of speaking.
For more information about childhood stuttering, you can also read Sounderic's guide to facts about stuttering in children.
What Are the 3 Types of Stuttering?
The three commonly recognized core stuttering behaviors are:
Repetitions
Prolongations
Blocks
Let's look at each one more closely.
1. Repetitions
Repetitions happen when a sound, syllable, or word is repeated more than once before the speaker moves forward.
For example, a child might say:
“B-b-b-ball.”
Or:
“Can-can-can I have that?”
The repeated element can occur at different levels.
Sound Repetitions
A person may repeat an individual sound:
“M-m-m-mom.”
Syllable Repetitions
A syllable may be repeated:
“Ba-ba-baby.”
Whole-Word Repetitions
A person may repeat an entire word:
“I—I—I want juice.”
Sound and syllable repetitions are commonly associated with stuttering. However, not every repetition that occurs during speech is necessarily stuttering.
For example, young children may repeat whole words or phrases while developing language, especially when they are excited or trying to organize their thoughts.
The broader speech pattern, frequency, tension, and context are important when determining whether a child is experiencing stuttering.
2. Prolongations
A prolongation occurs when a person stretches or holds a sound for longer than expected.
For example:
“Mmmmmommy, look!”
Or:
“Sssssstop.”
The person may know exactly what they want to say, but the sound continues instead of moving naturally into the next sound.
Prolongations can happen on vowel or consonant sounds and may vary in duration.
For some people, a prolongation may be relatively subtle. For others, it may be accompanied by noticeable physical tension or effort.
It's also possible for someone to experience both prolongations and repetitions during the same conversation.
3. Blocks
A block occurs when there is a temporary interruption in the flow of speech and the person has difficulty getting the sound or word out.
For example, a person may intend to say:
“My name is Alex.”
but experience a silent moment before being able to produce the first sound:
“My name is … Alex.”
During a block, the speaker may know what they want to say but temporarily feel unable to produce the word.
Some blocks are silent, while others may involve audible tension or effort.
A person experiencing a block might:
Tighten their lips
Press their tongue against the roof of their mouth
Hold their breath
Tighten their jaw
Try repeatedly to initiate the sound
Blocks can sometimes be particularly frustrating because the speaker may feel that the word is “stuck.”
What Do the 3 Types of Stuttering Have in Common?
Although repetitions, prolongations, and blocks look and sound different, they all involve interruptions in the normal flow of speech.
A person who stutters may experience:
Repetition → a sound, syllable, or word is repeated
Prolongation → a sound is stretched or held
Block → speech temporarily stops or becomes difficult to initiate
A person can experience one, two, or all three types of behaviors.
The pattern can also change over time. Someone who primarily experiences repetitions at one point may later experience more blocks or prolongations.
Stuttering isn't necessarily the same every time a person speaks.
What Does Stuttering Look Like?
Stuttering isn't always limited to what you hear. Some people also develop physical behaviors while trying to move through a moment of stuttering.
These may include:
Eye blinking
Facial tension
Head movements
Jaw tightening
Hand or arm movements
Foot tapping
Changes in breathing
Increased muscle tension
These behaviors are sometimes called secondary behaviors.
They don't occur in everyone who stutters. They may develop as a person tries to escape from or avoid a difficult speaking moment.
For example, a child who is having difficulty starting a word might blink repeatedly, move their head, or change their body position while trying to produce the word.
The presence of these behaviors does not necessarily tell you how severe a person's stuttering is. What matters is the individual's overall experience and how stuttering affects communication.
What Are Secondary Stuttering Behaviors?
Secondary behaviors are actions that may occur alongside moments of stuttering. They can develop when a person tries to get through, escape from, or avoid a moment of stuttering.
Examples can include:
Eye blinking
Facial movements or grimacing
Head movements
Jaw or lip tension
Tapping or other body movements
Changes in breathing
Looking away
Adding extra sounds or words
Not everyone who stutters develops secondary behaviors. Some people stutter with little visible physical tension, while others may experience significant effort or struggle.
It's also important not to assume that these behaviors are intentional. They may happen automatically as the person attempts to manage a difficult speaking moment.
What Is the Difference Between Stuttering and Typical Disfluency?
Everyone experiences some degree of speech disfluency. Pausing, repeating a word, using fillers such as "um" or "uh," and changing a sentence while speaking are normal parts of communication.
For example, a child might say:
"I, I, I want the blue one."
A single whole-word repetition does not automatically mean the child is stuttering.
Children may also go through periods when they repeat words or phrases as their language skills develop. This can sometimes be referred to as typical developmental disfluency.
Stuttering-like disfluencies are more likely to include:
Sound repetitions such as "b-b-ball"
Syllable repetitions such as "ba-ba-baby"
Prolongations such as "ssssun"
Blocks where speech becomes temporarily stuck
Noticeable physical tension or struggle
Increasing concern or frustration about speaking
Avoidance of words or speaking situations
However, there is no single behavior or number of repetitions that can determine whether a child stutters.
An SLP considers the broader pattern, including the child's speech, language development, history, communication environment, and reactions to speaking.
If you're unsure whether your child's disfluencies are typical or may represent stuttering, a speech-language evaluation can provide a more individualized answer.
Does Stuttering Change Depending on the Situation?
Yes. Stuttering can vary considerably from one situation to another.
A person might stutter more when:
Speaking in front of a group
Talking to someone unfamiliar
Answering questions quickly
Feeling rushed
Using the telephone
Speaking about an unfamiliar subject
Experiencing excitement or frustration
They might stutter less when:
Talking with someone they trust
Speaking alone
Singing
Talking in a familiar environment
Speaking in a relaxed situation
This variation can sometimes make stuttering confusing for parents. A child might appear to speak fluently at home but stutter noticeably at school or around unfamiliar people.
This doesn't mean that the child is pretending to stutter or that the stuttering is simply caused by nervousness. Stuttering is a complex fluency disorder, and speech fluency can naturally fluctuate.
Why Does My Child Stutter Sometimes but Not Others?
Fluctuation is common in childhood stuttering.
A child may have periods when their speech is relatively fluent and other periods when repetitions, prolongations, or blocks occur more frequently.
The amount of stuttering can change depending on the child's communication environment, speaking demands, and other factors.
For this reason, parents shouldn't assume that a child has "stopped stuttering" simply because they have had several fluent days.
Similarly, a temporary increase in stuttering doesn't necessarily mean that the child's communication abilities are getting worse.
If changes continue or you're concerned about your child's speech, an SLP can help determine whether an evaluation would be appropriate.
What Should Parents Do When a Child Stutters?
One of the most helpful things parents can do is create a comfortable environment where the child feels that they have time to communicate.
Listen Without Interrupting
Allow your child to finish what they are saying.
Try not to complete their sentences or supply words when they appear to be having difficulty.
Even when you know what your child is trying to say, giving them time communicates that what they have to say matters more than how quickly they say it.
Maintain Natural Eye Contact
Continue interacting naturally rather than looking away because your child is stuttering.
A relaxed, attentive response can help communicate that you are listening to the message rather than judging their speech.
Avoid Telling Them to “Slow Down”
Parents are often told to encourage a child to slow down, take a breath, or start again.
Although these suggestions may seem helpful, repeatedly correcting a child's speaking rate can make the child more aware of how they are speaking rather than what they are trying to communicate.
Instead, adults can model a relaxed conversational pace themselves.
Don't Finish Their Words
When a child is struggling to get a word out, it can be tempting to finish the sentence.
Try to resist that urge.
Finishing a child's words can unintentionally communicate that their speech needs to be rushed or completed by someone else.
Give them the time they need.
Focus on the Message
Respond to the content of what your child says.
For example, if your child takes several attempts to tell you about something that happened at school, focus on the story rather than correcting the repetitions.
This helps create a communication environment in which the child knows that their ideas and experiences are valued.
For additional parent-focused strategies, you can read Sounderic's guide to tips for helping your child with stuttering.
When Should a Child Who Stutters See an SLP?
Parents don't need to wait until stuttering becomes severe before seeking professional guidance.
Consider talking with an SLP if:
Your child's stuttering has continued over time
You notice frequent repetitions, prolongations, or blocks
Your child appears physically tense while speaking
Your child becomes frustrated about talking
Your child avoids certain words or situations
Your child says they don't want to talk
Stuttering appears to be increasing
There is a family history of persistent stuttering
You or your child are concerned about the speech pattern
An SLP can assess the child's fluency as well as their broader speech and language development.
The evaluation may consider how frequently the child stutters, the types of disfluencies occurring, physical tension, avoidance, the child's reactions to stuttering, family history, and how stuttering affects everyday communication.
There isn't a requirement that a child must reach a particular number of repetitions before an evaluation becomes appropriate.
Can Childhood Stuttering Go Away on Its Own?
Childhood stuttering can change considerably over time, and some children eventually stop stuttering.
However, it isn't possible to know with certainty from a single observation whether a particular child's stuttering will persist.
An SLP may consider several factors when assessing the likelihood of persistent stuttering, including:
Family history
How long the child has been stuttering
The child's age when stuttering began
Changes in the frequency or severity of stuttering
The child's language development
Physical tension
The child's response to stuttering
Some children recover naturally, while others continue to stutter into adolescence or adulthood.
This is one reason why an individualized assessment can be useful rather than relying on a simple rule such as "wait and see."
How Can Speech Therapy Help With Stuttering?
Speech-language therapy for stuttering is individualized. The goal isn't necessarily to eliminate every moment of stuttering.
Depending on the person, therapy may focus on:
Improving communication confidence
Reducing physical tension during stuttering
Learning strategies for managing moments of stuttering
Reducing avoidance
Increasing participation in conversations
Supporting communication in school or work settings
Helping parents create a supportive communication environment
Different therapeutic approaches may be appropriate for different people.
For example, some approaches focus on modifying the way a person moves through moments of stuttering, while others may focus more heavily on reducing the impact that stuttering has on communication and participation.
Sounderic's guide to fluency shaping techniques and strategies for stuttering provides more information about one group of approaches.
The goal of therapy should be based on the individual's needs and communication priorities rather than simply making their speech sound perfectly fluent.
Stuttering vs. Cluttering: Are They the Same?
No. Stuttering and cluttering are different fluency disorders, although a person can experience characteristics of both.
Stuttering primarily involves interruptions in the flow of speech such as repetitions, prolongations, and blocks.
Cluttering can involve unusually rapid or irregular speech, reduced intelligibility, irregular pauses, and other characteristics that affect the organization and flow of speech.
Because the two conditions can sometimes appear similar, an SLP can help determine what is contributing to a person's communication difficulties.
You can learn more about the distinction in Sounderic's article on stuttering vs. cluttering.
Final Thoughts
The three commonly discussed types of stuttering—repetitions, prolongations, and blocks—describe different ways that speech may become interrupted.
A person who stutters may experience one of these behaviors or a combination of them. They may also experience physical tension, secondary behaviors, avoidance, or changes in how comfortable they feel communicating.
For children in particular, occasional disfluency doesn't automatically mean that they stutter. What matters is the overall pattern, how long it has been present, the types of disfluencies involved, and how the child experiences communication.
If you're concerned about your child's speech, an SLP can help you understand what you're seeing and determine whether evaluation or support would be useful.
Most importantly, give children time to communicate. Listen to what they are saying, rather than focusing only on how smoothly they say it.
