Singular and plural. Words with unusual plural forms

The content of these guidelines is taken from the Vives University Network’s Interuniversity Style Guide for Writing Institutional Texts, an interuniversity project in which the UPC participated with the support of the Secretariat for Universities and Research of the Government of Catalonia.

Words with unusual plural forms

• Some frequent examples in our institutional context are campus, curriculum, practicum and thesis, which take the plural forms campuses, curricula, practicums and theses, respectively. Because the standard English plural -s is becoming increasingly widespread, in those cases where you can choose between two alternative plural forms this guide recommends the -s form (for example, prefer syllabuses to syllabi).
  
  
• For a longer list of unusual plural forms, see Unusual plural forms.