Dictionary-enhanced plural guide
What is the Plural of “Parenthesis”?
Learn the singular and plural noun forms, the rule behind the plural, and examples that show the form in context.
Singular and Plural Form of Parenthesis
Parenthesis is the singular noun form. Parentheses is the plural form.
Dictionary meaning: A curved bracket ( ) placed around extra information that could be removed without changing the main meaning.
Why is the Plural of Parenthesis “parentheses”?
The Irregular Plural Rule for Parenthesis
This noun has an irregular plural form that does not follow standard English pluralization rules.
Plural pattern: irregular.
How to Remember the Plural of Parenthesis
“parenthesis” → “parentheses” is an irregular plural — there is no rule, so memorise the pair as a whole. Try writing it in 3 sentences today.
A common slip-up: Saying pa-ren-THEE-sis instead of pa-REN-thuh-sis..
Singular vs Plural Examples with Parenthesis
See parenthesis and parentheses used in real sentences side by side.
- Add your phone number in parenthesis after your name. A2
- I put the translation in parenthesis so readers could skip it. B1
- The author inserted a historical note in parenthesis within the argument. B2
Common Plural Mistakes with Parenthesis
Wrong: The plural of parenthesis is parenthesises.
Correct: The plural of parenthesis is parentheses.
Greek -is nouns form plurals with -es, not -ises
Wrong: Put the note in parenthesis.
Correct: Put the note in parentheses.
A pair of brackets is always parentheses (plural), not the singular form
How to Pronounce Parenthesis and Parentheses
Four syllables: pa-REN-thuh-sis. Stress on second syllable. 'th' sounds as in 'think'.
Other Words With the Same Plural Pattern as Parenthesis
These nouns follow the same irregular rule. Click any word to see its plural page.
A young boy or girl who is not yet an adult.
the two parts at the bottom of your legs that touch the…
A tiny insect that lives around food and moves very fast.
One of two equal parts that make up something complete.
A grown-up male person. A man is an adult male, not a…
The ability to remember things from the past, or the thought you…
One human; a single individual.
Money that a person earns from their job, paid regularly by their…
Origin and Etymology of Parenthesis
From Greek parenthesis (insertion): para- (beside) + en- (in) + tithenai (to place).
Cultural note: 'In parenthesis' also means adding an aside or digression to a speech or piece of writing.
Frequently Asked Questions About the Plural of Parenthesis
What is the plural of “parenthesis”?
The plural of “parenthesis” is “parentheses”.
Is “parentheses” regular or irregular?
This page classifies it as irregular based on the available plural data.