Why Are Sounds Like "r", "th", /l/, /s/, or /z/ Difficult for My Child?

Have you noticed your child saying “fink” instead of “think,” “wabbit” instead of “rabbit,” or “wun” instead of “run”? If so, you may be wondering whether your child's speech sound development is on track.

Learning to produce speech sounds is an important part of childhood speech development. Some sounds are easier for children to learn, while others require more precise and coordinated movements of the tongue, lips, jaw, and other structures involved in speech.

Sounds such as "r", "th", /l/, /s/, and /z/ can take longer to develop and may continue to be challenging for some children as they get older.

When Do Children Learn Speech Sounds?

Children typically develop speech sounds gradually. Research on English-speaking children has found that some consonants are generally acquired earlier than others (McLeod & Crowe, 2018; Crowe & McLeod, 2020).

Speech sounds can be broadly grouped into early-, middle-, and later-developing sounds:

Developmental stage	Examples of sounds
Earlier developing	/p, b, m, d, n, h, t, k, g, w, ng, f, y/
Middle developing	/l, ch, s, v, sh, z/
Later developing	/r, th, zh/

These age ranges are general developmental guidelines, not strict deadlines. Children develop speech sounds at different rates, and factors such as language background, the type of speech sound difficulty, and a child's overall speech development can influence when particular sounds become consistent.

McLeod and Crowe (2018) examined consonant acquisition across 27 languages, highlighting that speech sound development can also vary across languages. For children who speak more than one language, it is important to consider the child's entire linguistic background when evaluating speech development.

Why Are Some Speech Sounds More Difficult?

Producing a speech sound requires precise coordination of several movements. The tongue, lips, jaw, and other structures need to move into specific positions while coordinating airflow and voicing (Namasivayam et al., 2020).

For example, producing /s/ requires the tongue to create a narrow channel for airflow while the sides of the tongue are positioned appropriately. Small differences in tongue placement or airflow can change how the sound is produced.

The "r" sound can be particularly challenging because it requires complex coordination involving different parts of the tongue and the vocal tract. Children may need to learn a very precise tongue position and coordinate it with airflow and voicing.

This is one reason why a child may be able to produce some sounds clearly but continue to have difficulty with others.

Why Does My Child Say “Fink” Instead of “Think”?

When a child has difficulty producing a particular sound, they may substitute one sound for another.

For example:

• “fink” instead of “think”

• “wabbit” instead of “rabbit”

• “wed” instead of “red”

• “tun” instead of “sun”

  
  

These patterns are known as speech sound errors or phonological patterns, depending on the nature of the difficulty.

Some children have difficulty learning the movements needed to physically produce a sound. Others may be able to produce the sound in certain situations but have difficulty using it consistently within words and connected speech. Speech sound disorders can therefore involve different underlying areas of speech production and processing (Harding et al., 2024).

Why Can My Child Say a Sound Sometimes but Not Others?

Parents sometimes notice that their child can produce a sound during practice but does not use it consistently during everyday conversation.

This can happen because producing an individual sound is different from using that sound accurately and automatically in words, sentences, and conversation.

For example, a child may be able to say "r" when asked to repeat a particular word but still say it differently when talking quickly in a conversation.

An SLP can look at where and when speech sound errors occur, whether the errors are consistent, and how the child's speech is understood by others.

When Should I Be Concerned About My Child's Speech Sounds?

It is normal for young children to make some speech sound errors as they learn to talk.

However, an assessment with a speech-language pathologist (SLP) may be helpful if:

• Your child's speech is difficult for family members or unfamiliar listeners to understand.

• Your child continues to have difficulty with sounds that are expected to be developing at their age.

• Your child leaves sounds out, substitutes sounds, or changes sounds frequently.

• Your child becomes frustrated when trying to communicate.

• Your child avoids saying certain words because they are difficult to pronounce.

• You notice that your child can produce a sound during practice but has difficulty using it in everyday speech.

• You are simply concerned about your child's speech development.

You do not need to wait until a child reaches a particular age before asking questions about their speech. An SLP can assess your child's individual speech development and help determine whether their speech patterns are consistent with typical development or whether additional support may be beneficial.

How Can a Speech-Language Pathologist Help?

A speech-language pathologist can assess your child's speech sounds and determine which sounds or patterns may be affecting their communication.

An assessment may look at:

• Which sounds your child can produce

• Which sounds are difficult

• Where errors occur within words

• Whether errors are consistent or variable

• How understandable your child's speech is to different listeners

• Your child's ability to produce sounds in words and connected speech

• Whether speech sound difficulties are affecting communication

If therapy is recommended, an SLP can develop individualized goals and activities to help your child learn more accurate and consistent speech sound production.

Speech Therapy for Speech Sound Difficulties in Vaughan, Ontario

If you are concerned about your child's pronunciation or speech development, a speech-language pathologist in Vaughan can help you understand what may be contributing to your child's speech sound difficulties.

At Kurliand Speech Clinic, we provide speech-language assessments and therapy for children in Vaughan, Woodbridge, Maple, and surrounding communities. We offer in-clinic and in-home speech therapy in Vaughan, as well as virtual services across Ontario.

Whether your child is having difficulty with "r", "th", /l/, /s/, /z/, or other speech sounds, an individualized assessment can help identify their strengths and determine whether speech therapy may be appropriate.

Concerned about your child's speech sounds? Contact Kurliand Speech Clinic to learn more about speech therapy for children in Vaughan, Ontario.

References

Crowe, K., & McLeod, S. (2020). Children's English consonant acquisition in the United States: A review. American Journal of Speech-Language Pathology, 29(4), 2155–2169. https://doi.org/10.1044/2020_AJSLP-19-00168

Harding, S., Burr, S., Cleland, J., Stringer, H., & Wren, Y. (2024). Outcome measures for children with speech sound disorder: An umbrella review. BMJ Open, 14(4), e081446. https://doi.org/10.1136/bmjopen-2023-081446

McLeod, S., & Crowe, K. (2018). Children's consonant acquisition in 27 languages: A cross-linguistic review. American Journal of Speech-Language Pathology, 27(4), 1546–1571. https://doi.org/10.1044/2018_AJSLP-17-0100

Namasivayam, A. K., Coleman, D., O'Dwyer, A., & van Lieshout, P. (2020). Speech sound disorders in children: An articulatory phonology perspective. Frontiers in Psychology, 10, 2998. https://doi.org/10.3389/fpsyg.2019.02998