The Difference Between Decodable and Non-Decodable Words

By The Understood Team

At a Glance

  • Knowing the relationship between letters and their sounds helps kids decode words.

  • Some words are tricky and don’t follow the rules of phonics.

  • Words that kids learn to recognize at a glance are called sight words. Some are decodable but many are not.

Early readers must know how to tackle and instantly recognize two types of words to read fluently. One is decodable words; the other is non-decodable words. For kids with reading issues, including dyslexia, learning to read both types of words can be a challenge.

This chart can help you know the difference between decodable words and non-decodable words, and what can help your child learn both.


Decodable words Non-decodable words
What they are

Words that kids can sound out using the rules of phonics.

Examples include: pot, flute, and snail.

Words that can’t be sounded out and that don’t follow the rules of phonics. They need to be memorized so they’re instantly recognizable. These are sometimes called sight words, or star words.

Examples include: right, enough, and sign.

(Note: Some decodable words are also taught as sight words. These words are used so frequently that kids need to recognize them instantly.)

Skills required

Kids need to have phonemic awareness (part of a broader skill called phonological awareness). This skill allows students to rapidly map sounds to letters and blend sounds to read words.

Kids also rely on working memory to help them keep in mind the sounds at the beginning of a word as they decode the rest of the word.

Kids need good memory skills to store words in their long-term phonological memory.

That allows them to quickly retrieve words when they see them. Kids turn a word into a sight word by mapping unexpected (non-phonetic) sequences of letters to their sounds.

Kids need fast-enough processing speed to read words automatically and fluently.

How these words are taught

For kids with reading challenges such as dyslexia, teachers typically use multisensory structured language education (MSLE). That includes multisensory techniques to help kids connect letters to sounds.

One such teaching approach is Orton–Gillingham. A few reading programs are based on this approach.

There are also other reading programs that are mainly used in general education. In the early grades, these programs focus on decoding skills.

Teachers introduce groups of words to students, based on grade level. Students may take these words home and work on memorizing them. Kids learn best when working and practicing with small groups of words on a regular basis until the words are instantly recognizable.

It can help if students practice reading these words in meaningful sentences.

It can also help to find the irregular part of the word and highlight it to make it easier to remember. For example, in the word said, the irregular part of the word is ai.

What kids need to know

There are rules that can help them sound out words.

Some common words don’t follow rules and can’t be sounded out. These words need to be memorized. Words with similar meaning or similar spellings can be learned in groups. For example, these ight words: right, night, flight.

How you can help

There are multisensory techniques and tools parents can use to teach phonics, such as color-coded word building tiles.

There are also strategies for building phonological awareness at different ages.

There are strategies for teaching non-decodable words to struggling readers.

Parents can review lists of sight words, including non-decodable words, with their child. They can talk about the letter patterns in irregular sight words that don’t follow the rules.

If your child is struggling with reading and you’re concerned the cause might be dyslexia, there are steps you can take. Your child might be eligible for special education services and supports at school that can help.

Also, hear an expert explain why learning to read is harder than learning to speak. And learn about how different learning and thinking differences make it hard to read.

Key Takeaways

  • Learning to read involves both decoding and recognizing sight words at a glance.

  • High-frequency words can be decodable or non-decodable.

  • Struggling readers may benefit from multisensory reading instruction.

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