Plural of Chassis
“Chassis” has the same written form in singular and plural. Number is shown by context, determiners, quantities, agreement, and—when spoken—a plural pronunciation ending in a /z/ sound. Do not create a written plural “chassises.”
The plural of “chassis” is spelled “chassis,” the same as the singular; dictionaries mark a different plural pronunciation.
Key details
Choose the right form
| Meaning / situation | Form / construction | Decision |
|---|---|---|
| one frame | a chassis / one chassis | Singular spelling. |
| more than one frame | chassis | Same written plural. |
| spoken plural | plural pronunciation ending in /z/ | Pronunciation distinguishes number. |
Quick tests
Plural-choice test
Are you referring to more than one chassis?
If yes: Keep the spelling “chassis” and use plural context/agreement.
If no: Use “a chassis” or another singular construction.
Caveat: The spelling is invariant, so written number must be clear from surrounding words when context could be ambiguous.
Examples
The manufacturer tested three chassis.
Plural keeps the same spelling.
This chassis supports the new body.
One takes the same written form.
Several chassis were stored outside.
Plural agreement and quantity show number.
Further guidance
Core difference
Write “chassis” for both singular and plural; pronunciation distinguishes the plural in speech.
Fast Test
Use quantities and surrounding grammar to make written number clear.
Usage Boundary
Do not add “-es” to create “chassises.”
Sources and evidence
Sources are shown with the role they play in this guide. Historical or style-sensitive claims are kept within the evidence boundary described above.
- CHASSIS Definition & Meaning - Merriam-Webster (opens in a new tab)Merriam-Webster · Merriam-Webster records chassis as the plural spelling of chassis, with a plural pronunciation ending in /-z/.
- CHASSIS | English meaning - Cambridge Dictionary (opens in a new tab)Cambridge University Press · Cambridge records plural chassis with the same spelling and a distinct plural pronunciation.