The Plural of Series: Here’s What It Is and How to Use It

Have you ever been stuck wondering what the plural form of series is in English? This is one of the words that can easily trip you up, whether you are a laypeople or not,  if you haven’t thought of it before or in a while. This article will also cover the definition of series, the history and origin of the word, usage notes, synonyms from a thesaurus, and examples of the word series in context to help you fully understand the word.

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What Is the Definition of the Word Series

As the unabridged version Merriam-Webster phrases it:

  • a number of things or events of the same class one after another in spatial or temporal succession
    • A concert series
    • The hall opened into a series of small rooms
  • a set of regularly presented television programs each of which is complete in itself 
  • The indicated sum of a usually infinite sequence of numbers
  • The coins or currency of a particular country and period
  • The group of postage stamps in different denominations 
  • A succession of volumes or issues published with related subjects or authors, similar format and price, or continuous numbering such as in a podcast or a set of radio.
  • A division of rock formations that is smaller than a system and comprises rocks deposited during an epoch
  • A group of chemical compounds related in composition and structure 
  • An arrangement of the parts of or elements in an electric circuit whereby the whole current passes through each part or element without branching
  • A set of vowels connected by a laur (such as i, a, u in ring, rang, rung)
  • A number of games (as of baseball) played usually on consecutive days between two teams
    • In town for a 3 game series
  • A group of successive coordinate sentence elements joined together 
  • Soil series
  • Three consecutive games in bowling

It is important that series can be used as noun, but also as a singular verb or plural verb. 

History and Origin of the Word

The first known or recorded time in history that the word series was used was in 1611. It was used in the sense of “a number of things or events of the same class coming one after another in spatial or temporal succession”. 

The word series comes from the Latin language. Join in Latin is serere which means to join together or bind, this is similar grammatically to the Greek word eirein which literally translates to English as to string together. 

Is Serieses a Word?

If you have ever tried to type out serieses, you would see a little red line underneath it, what is the plural form of series then? While you may think the plural would be seri or seria, series is one of many words in the English language that is the same in both the singular sense and plural sense.

Is or Are After a Series?

This is actually a little more of a tricky subject in grammar than you might think. Just above this question, we discussed that series is both the singular and plural form of the word in the English language. Because the context of the word and whether it is singular or plural will decide whether you use the is (for the singular form of series) or are (for the plural form of series).


  • Array – collection, considerable group
  • String – succession, series
  • List – record, tabulation 
  • Run – sequence, course
  • Sequence – series, order
  • Set – group, assortment
  • Streak – vein, line; small part

Examples of the Word in Context

  • French officials were already on edge after a series of apparently unconnected attacks, including the stabbing of police officers. – U.S. Spies See Al Qaeda Fingerprints on Paris Massacre – Shane Harris, Nancy A. Youssef – January 8, 2015 – Daily Beast
  • Life is a series of seemingly throwaway moments strung together in a peculiar tapestry, and Linklater has captured it beautifully. – Oscars 2015: The Daily Beast’s Picks, From Scarlett Johansson to Boyhood – Marlow Stern – January 6, 2015 – Daily Beast
  • The world series for baseball are related things to the playoffs in American football, many of which are held in New York.
  • Conway goes on to list a series of other coincidences that he suggests are not simply explained. – Harry’s Daddy, and Diana’s ‘Murder’: Royal Rumors in a New Play – Tom Sykes – January 4, 2015 – Daily Beast
  • All of these far-future speculations, of course, depend on a series of “ifs.” – Men Will Someday Have Kids Without Women – Samantha Allen – January 3, 2015 –  Daily Beast
  • But throughout the series so far, its style has also had a profound story of its own to tell. – What Downton’s Fashion Really Means – Katie Baker – January 2, 2015 – Daily Beast
  • The position of those who remained was regulated in a series of decrees, adverse to the system, but favourable to the inmate. – Lectures on the French Revolution – John Emerich, Edward Dalberg  – Gutenberg 
  • The principal work is his series of Lectures in the Royal Academy, twelve in number, commenced in 1801. – Encyclopedia Britannica, 11th Edition, Volume 11, Slice 3
  • The two armature coils are in series circuit with the field-coils and the same disposition of the shunt or short-circuit D is used. – The Inventions, Researches and Writings of Nikola Tesla – Thomas Commerford Martin
  • After a series of farewells that would have befitted an imminent voyage to foreign parts, the Kid went down to the street. The Voice of the City – O. Henry
  • In the Liquozone article of this series I showed how medical evidence is itself “doctored.” – The Great American Frauds – Samuel Hopkins Adams
  • The first to come to mind is, of course, ABC’s “Cavemen,” a 2007 sitcom based on a series of Geico insurance ads that was famously awful. It turned a trio of cavemen, made up with suburban-Halloween-level hairiness, into members of a minority mistreated by — not kidding — “sapes,” or homo sapiens. Also in the Hall of Shame for series based on ads: CBS’s “Baby Bob” from 2002, the talking infant that was adapted from an ad for – ‘Ted Lasso’ is a true anomaly — a TV series or television series adapted from an ad that’s actually worth watching 
  • CIO Summit Virtual Series, powered by Zoom, will again convene the world’s leading Chief Information Officers. On September 2, the third event in the four-part virtual series will take place, focusing on “Rebooting Growth Through Digital-First Innovation.” – Forbes CIO Summit Virtual Series Part Three Focusing On “Rebooting Growth Through Digital-First Innovation”