Have you tried Elkonin boxes? Elkonin boxes are a great resource to help students effectively segment words by sound. The boxes help children segment words into the smallest unit of sound – phoneme. The boxes have to be all the same size, and each sound goes in one box, not each letter goes in one box. We add the letter or letter string representing a single sound to one box.
So the word chair has five letters but only two graphemes. To teach reading and spelling in the most effective way possible, we should not split the word chair into five letters. The c and h go together to represent the sound /ch/ they don’t represent their initial sounds /c/ /h/, and the a, i and r don’t represent their initial sounds either. They represent the vowel sound /air/ or you might say /ay/ /r/ depending on accent.
Spelling out the word using individual letters will confuse your little learner when they try to decode, segment or blend sounds to make words and read fluently.
The word chair should be split into sounds, not letters.
/ch/ /air/ 2 graphemes, 2 sounds for many. Some will sound the R so the word may be 3 sounds.
Segmenting words into individual sound units is a positive habit for both reading and spelling. The ability to hear individual sounds within words is called phonological awareness, and this broad term encompasses rhyming, alliteration, sound manipulation and segmentation.
Use the boxes to tie the written letter or letter string to the sound. It requires the ability to unconsciously connect the grapheme to the sound for fluent reading. Use the boxes with either my movable alphabet or laminated with a whiteboard marker. This activity has great value as it draws attention to the individual sounds within words and requires careful listening.
I often see Elkonin boxes used with counters to represent sounds. I see these boxes as a tool to encourage the sound-symbol correspondence. There is added value if we always add the letter symbol or grapheme to the required box to build the word. This develops the segmenting and blending skills required for fluency.
Segmenting—I can build the word. I can write the word.
Blending—I can blend the sounds and connect to letters and groups of letters to read the word.
If you don't like the idea of the boxes — lines work just as well. Just make sure to use one line per sound, not one line per letter. I often use lines on whiteboards to scaffold dictation activities.