relation / relationship

Relationship can describe a connection between two people (this connection may be romantic or not):

  • I’ve been dating my boyfriend for three years. We have a great relationship.
  • He has a terrible relationship with his father.
  • My sister and I have a good relationship.

    Both relationship and relation can describe connections between two things or ideas:

  • I’m studying the relationship between education levels and poverty.
  • There’s a close relation between smoking and lung disease.

    The word relations (plural) is used with general connections in a specific category:

  • international relations
  • diplomatic relations
  • public relations
  • race relations
  • sexual relations etc.

    Although relations can mean the people who are biologically related to you, it’s more common to call these people relatives.