There are not many English words shorter than or - 2, to be precise. But being short is no guarantee of being unambiguous, as the following sentences will show.

Quiz

What does or mean here?

• Would you like tea or coffee?
• Colour the sea green or blue.
• Many slaves fought in the American Revolution or War of Independence.

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Answers

• Would you like tea or coffee?

  This is the common and easy use of or. You can have tea or you can have coffee.

• Colour the sea green or blue.

  This could be a request from the art teacher, but does it mean: You must colour the sea either all green or all blue? Or does it mean: You may use blue and green for the sea, in any combination of the two colours? There is no way of knowing.

• Many slaves fought in the American Revolution or War of Independence.

  In this case or does not mean that slaves fought either in the American Revolution or in the War of Independence. Nor, of course, does it mean that they fought in both of these periods. Or is used to introduce an alternative term for American Revolution.

  This might not seem particularly difficult, but put yourself in the position of being an ESL student reading these homework instructions:

  • Draw a pie graph or chart to show your results.
  • Next, cut up an aubergine or eggplant.
  The use of the word or here implies in both sentences that the student has a choice of what to draw or what to cut up, which is not the case. If the words are new to the student, the teacher has unwittingly added a small degree of unnecessary ambiguity and complexity to the homework task.