In general, we use apostrophes to indicate possession or contracted forms.

  • Possessive forms of nouns

    The possessive form of a singular noun is marked by an apostrophe followed by s.

    Exemple correcte the manager’s report
    Exemple correcte the lecturer’s hypothesis

    This rule applies in most cases even with a name ending in -s.

    Exemple correcte the PAS’s response
    Exemple correcte Erasmus’s success

    If a plural noun already ends in -s, the apostrophe is used alone.

    Exemple correcte the students work (several students)
    Exemple correcte the teachers room (all the teachers)

    Note that the apostrophe is also used in expressions of time.

    Exemple correcte eight weeks time
    Exemple correcte yesterdays meeting

    Degree types should be written with an apostrophe followed by s.

    Exemple correcte bachelor’s degree
    Exemple correcte master’s degree

    But note the exception doctoral degree (not doctor’s degree).

    Do not use apostrophes to indicate a decade, a plural acronym or the plurals of figures.

    Exemple incorrecte the 1990’s
    Exemple correcte the 1990s
    Exemple incorrecte URL’s
    Exemple correcte URLs
    Exemple incorrecte 747’s
    Exemple correcte 747s

  • Contractions

    Use apostrophes for contractions (you’re for you are, don’t for do not, it’s for it is or it has) but note that contractions are far less common in formal texts than they are in informal writing.
Darrera actualització: 7-11-2017
Impressió del capítol | Impressió de la pàgina
Recommended citation:
«Apostrophes» [en línia]. A: Llibre d’estil de la Universitat de Barcelona. Barcelona: Universitat de Barcelona. Serveis Lingüístics. <http://www.ub.edu/cub/criteri.php?id=2312> [consulta: 7 juliol 2022].