Understanding how to correctly use singular and plural forms of words in English is essential for clear and accurate communication. One word that often confuses both native and non-native speakers is parenthesis.” It’s a term used frequently in writing and grammar discussions, yet many people hesitate when it comes to its plural form. Is it “parentheses,” “parenthesises,” or something else entirely? Knowing the correct plural form of “parenthesis” not only improves your grammar but also enhances your ability to write professionally and academically.
Definition and Use of “Parenthesis”
The wordparenthesisrefers to a punctuation mark or a word, phrase, or clause that is inserted into a sentence to provide additional information or clarification. This inserted material is typically placed between a pair of curved brackets ( ).
Examples of a Parenthesis in a Sentence
- He finally answered (after taking five minutes to think) that he didn’t know the answer.
- The capital of France (Paris) is known for its culture and history.
In these examples, the information within the parentheses adds extra detail but is not essential to the main sentence. If removed, the sentence still makes sense. This is the core function of a parenthesis.
What Is the Plural Form of Parenthesis?
The correct plural form ofparenthesisisparentheses. This is one of many English words derived from Greek, and its plural follows the Greek convention, not the typical English “-s” or “-es” rule.
Parenthesis → Parentheses
Examples in Plural Use
- Please remove all unnecessaryparenthesesfrom your writing.
- The sentence contains multipleparenthesesthat interrupt the flow of thought.
As you can see, “parentheses” is used when referring to more than one parenthetical element or multiple sets of curved brackets used in writing.
Origin and Etymology
The wordparenthesiscomes from the Greek wordparentithenai, meaning “to put in beside.” The Greek noun formparenthesisliterally means a placing beside or an insertion. Because it comes from Greek, its plural form also follows Greek rules changing the “-is” ending to “-es,” just as with other words like
- Thesis → Theses
- Crisis → Crises
- Analysis → Analyses
These words may look similar but do not follow regular English pluralization. Knowing that “parenthesis” belongs to this group helps you remember its correct plural form.
Common Mistakes with “Parenthesis” and “Parentheses”
Because the singular and plural forms of “parenthesis” differ significantly in spelling and pronunciation, learners of English often make mistakes. Below are some common errors and how to avoid them.
Mistake 1 Using “parenthesis” when referring to more than one
IncorrectThe sentence contains two parenthesis.
CorrectThe sentence contains two parentheses.
Mistake 2 Adding “es” to form “parenthesises”
This error occurs when speakers apply standard English pluralization rules without considering the Greek origin of the word.
IncorrectI put three parenthesises in the paragraph.
CorrectI put three parentheses in the paragraph.
Mistake 3 Confusing the term with the punctuation marks
Some people think “parenthesis” refers to the bracket itself, while others use it to describe the content inside the brackets. In truth, it can refer to both, depending on context.
- The curved brackets themselves are also calledparentheses.
- The information inside the brackets is called aparenthetical statementor simply aparenthesis.
Parenthesis in Grammar and Punctuation
In grammar, a parenthesis is often classified as a type ofinterruptionin a sentence. While commas or dashes can also serve this role, parentheses (the punctuation marks) are especially useful for inserting extra thoughts or background information that are not vital to the main clause.
Function of Parentheses
Parentheses are used to
- Provide clarificationHe moved to Jakarta (the capital of Indonesia).
- Add afterthoughtsShe loves chocolate (who doesn’t?).
- Show abbreviations or acronymsNational Aeronautics and Space Administration (NASA)
- Include citations or references in academic writing
Singular vs Plural in Different Contexts
It’s essential to distinguish whether you’re referring to one instance or multiple instances of parenthesis in your writing.
Singular Example
SentenceOneparenthesisis used to explain the abbreviation.
Plural Example
SentenceSeveralparenthesesin the text make it hard to follow the main point.
Pronunciation Tips
Another area where confusion often arises is pronunciation. Here’s how to pronounce each form
- Parenthesis/pəˈrɛnθəsɪs/
- Parentheses/pəˈrɛnθəˌsiz/
The shift from “-sis” to “-sees” may seem unintuitive at first, but practicing with similar Greek-derived words can help make it more familiar.
Similar Words to Know
Many English words with Greek roots have irregular plural forms. Learning these will help you develop a deeper understanding of English grammar and vocabulary. Here are a few more
- Phenomenon → Phenomena
- Datum → Data
- Criterion → Criteria
Just like “parenthesis,” these words follow Greek pluralization rules and are often found in academic or scientific contexts.
Mastering the correct plural form of “parenthesis” is a small but meaningful step in improving your English grammar. The singular form is “parenthesis,” while the plural is “parentheses.” This distinction is important when writing clearly and accurately, especially in formal or academic contexts. By understanding the origin of the word, common errors, pronunciation, and how it’s used in various grammatical constructions, you can use both forms confidently. Whether you’re writing essays, reading technical documents, or editing your own work, knowing the difference between “parenthesis” and “parentheses” helps ensure clarity and correctness in your communication.