And/or – A Bad Case of Conjunctivitis

A good test for why a word or phrase is considered legalese is that lawyers tend to use it in legal documents but would never dream of using it in normal conversation. The term and/or is a good example. No one says “and/or” in normal speech (I hope). After reading yet another legal document peppered with this construct (it is not a word and you cannot really call it a phrase), I found myself asking why it is that lawyers seem so fond of it and whether its meaning is always as clear as they assume.


The expression and/or is what grammarians (yes, there is such a thing, it means someone who studies or writes about grammar) call a conjunction. A conjunction is a word or phrase which connects (coordinates would be a better word) phrases, clauses or sentences.


And/or has long history. It has been around since the mid-19th century and appears to have been the subject of criticism for almost as long. This criticism comes from:

  • grammarians, who make the point that it is not a real word;
  • proponents of clarity in legal writing, who note that it can lead to ambiguity; and
  • judges, who have called it “a bastard conjunction” and a “much condemned conjunctive-disjunctive crutch of sloppy thinkers”.

Problems with or

The main reason legal practitioners seem to prefer and/or is that or on its own can be ambiguous. It can be either exclusive, meaning A or B, but not both or inclusive, meaning A or B or both. One commentator notes that a good way of remembering this is that the word or carries a different meaning when we are asked:

  • “Would you like tea or coffee?” where it is used in an exclusive sense and when to answer “both” would seem very strange; or
  • “Would you like milk or sugar?” where it is used in an inclusive sense and when answering “both” is perfectly acceptable.

Drafters are nervous types who worry that by just using or they might not cover the situation where both A and B occur. They then try to make this clear by adding and; which gives us the and/or construct.

What does it mean?

The commonly accepted meaning of and/or is that it indicates that one or more of the cases it connects may occur. Put another way, it means either and or or or both. So the phrase A and/or B means:

  • A; or
  • B; or
  • both A and B.

Most of the time and/or works just fine. However, it is not a panacea. Depending on the grammatical context, the meaning of and/or can be unclear. Set out below are a few examples.


And/or can create ambiguity when it is used to frame an obligation. Take for example the provision “The joint venture company shall hire employees from shareholder A and/or shareholder B”. Would it satisfy that obligation if it hired employees only from shareholder A? Probably yes, but that meaning is a little unclear. Contrast this with “The joint venture company shall hire employees from shareholder A or shareholder B or both.” It then becomes much clearer that the company can choose to hire employees from only one of the shareholders.

Multiple cases

I often see and/or used where there are three or more cases (eg, A, B and/or C). Does this include A and B but not C? Again, probably yes, but that meaning is not as clear as it could be, particularly where, as is often the case, there is no other conjunction, such as and or or, between the A and the B.

Both Not an Option

Finally, and/or is often used in a lazy way where the only possible meaning is or. Consider the provision “The board meeting will be held in Hong Kong and/or New York.” The writer might have meant that the meeting could be held in two places at once (via video conference perhaps?) but more likely they meant it would be held in either Hong Kong or New York.

Unlearning a Bad Habit

One of the most useful and accessible works on plain language legal writing is Michèle Asprey’s excellent book “Plain Language for Lawyers”. One of the points Asprey makes in this book is that the hard part about improving our legal writing skills is “unlearning” all the bad habits we tend to pick up and cling to. The use of and/or is in my view a very good example of one of these rather bad habits. Our job as legal drafters is to think about what we mean and then use the right word or words. As the author also notes, the really challenging part of improving the clarity of our legal writing is putting what we have learned into practice when we are under pressure. It is all too easy to use and/or when we are too rushed to consider whether we mean and or or or both. If you stop to ask yourself that question the next time the issue arises when drafting a contract, pleading or other legal document, make sure you know the answer and then use the correct conjunction. Just don’t rely on and/or always doing that job for you. 

Kennedys, Partner