Well, yes it could be normal that your child cannot produce the /th/ sound, depending on their age. Children acquire speech sounds in a particular order with some being early developing and others being later developing. /th/ is one of those later developing sounds. We don’t expect children to be producing this accurately until they are about 8 years old. Of course children can acquire sounds earlier than the expected time frame.  Outlined below are the ages at which most children acquire the speech sounds.

0-1 years

In this age group children are usually experimenting with sound production and will babble. Their babble will begin to sound like real words. Between six to nine months you could expect babbling to commence. This babble usually contains sounds that are made with the lips (e.g. /b/ and /m/) which is often why their “first words” are words like ‘baba’ or ‘mama’. Between nine and 12 months, this babbling increases and the child will use more sounds, including: /d, m, n, h, w, t/ and they generally start to use single words. Single words are often short words and can be simplified forms of adult words (e.g. ‘dog’ -> ‘do’ or ‘woo’ (woof)).

1-3 years

During the toddler stage, children are experiencing a large development in their speech and language skills. They have an increased vocabulary and utterance length and they produce more speech sounds, making their speech easier to understand. Most of their speech (75%) should be understood by family and friends by the age of three.

At 2 years, your child should be able to produce the following sounds:

/p, b, m, t, d, n, h, w/

By 3 years, your child should be able to make the above sounds as well as these sounds:

/k, g, f, s, ng/

They should also be putting the sounds on the ends of their words (e.g. ‘hat’ not ‘ha’). They may continue to have difficulty with multisyllabic words (e.g. hospital) and words containing consonant blends (e.g. spoon). This is still age appropriate.

3-5 years

In the preschool years, a child’s speech and language skills are continually developing. They begin to use much longer sentences and by five years they should be understood 95-100% of the time by unfamiliar listeners. More complex word structures (e.g. multisyllabic words and consonant clusters) are emerging in their speech.

At 4-4;6 years of age, your child should be producing all of the sounds previously mentioned plus the following sounds:

/y, s, z, ch, sh, l, j/

At this age they should also be beginning to use consonant clusters (e.g. ‘Spider’, not ‘bider’) and their production of multisyllabic words should improve (e.g. ‘banana’ not ‘nana’).

5 years onwards

Once your child is at school, they should be using most speech sounds correctly. It is important for their speech sounds to be developed appropriately at this time as it may begin to impact on their spelling and literacy development if they cannot produce sounds correctly.

By the age of 6, you would expect your child to produce /r/ and /v/ correctly.

By the age of 8, you would expect the final sound, /th/ to be produced consistently.

If you have any concerns with your child’s speech and language development then contact a speech pathologist. If your child is not producing the sounds at the appropriate ages, then they may also benefit from a hearing test to ensure that they are hearing the sounds appropriately.

This blog is a modification of Speech Pathology Australia’s fact sheets: “The Sound of Speech: 0 to 3 years” and “The Sound of Speech: preschool and school aged children”. For more information the factsheets can be accessed at Speech Pathology Australia – Fact Sheets.