The -ast CVCC Word Family
The -ast family is a small group of CVCC words that share the same short a vowel and the same final blend. The words here are cast, fast, last, mast, past, vast.
Families matter more at CVCC than at CVC, because the ending is now two sounds instead of one. Once a child has the ending “ast” automatic, every new word in the family only asks them to change one sound at the front — which is the difference between decoding and guessing.
All 6 –ast Words
| Word | Build | Example sentence |
|---|---|---|
| cast | c + ast | Cast the line into the pond. |
| fast | f + ast | The car can go fast. |
| last | l + ast | This is the last one. |
| mast | m + ast | The sail hangs on the mast. |
| past | p + ast | Walk past the shop. |
| vast | v + ast | The sky looks vast at night. |
How to Teach the -ast Family
1. Read the ending first
Point to the last letters and say only that part. Do not add the first letter yet.
2. Add the first letter
Now blend the front sound in: cast, fast, last. Keep the ending identical every time.
3. Compare with a CVC word
Pair each CVCC word with a CVC word that starts the same way, so the child hears the extra final sound — for example han vs hand. See the CVC word lists.
4. Bring in the other CVCC families
Contrasting two families is where the learning consolidates: all CVCC words or the families below.
Other CVCC Word Families
-ast CVCC Family FAQ
How many -ast CVCC words are there?
6 on this page: cast, fast, last, mast, past, vast.
What sound does the -ast family make?
A short a (æ) followed by a blend: “ast”. Both consonants at the end are heard — unlike a digraph such as sh, where two letters make one sound.
What is the teaching order for -ast?
Say the rime first as two sounds, then add the opening consonant one at a time. Keep the ending identical and change only the front, so the child hears what stays the same.