# about Da vinci or Picasso.

#### Robby Zhu

##### Senior Member
Hi, everybody. How should students understand this description?

1. Teacher: The question in part 2 will be about Da vinci or Picasso.

Can students conclude from this that the teacher has excluded the possibility of the question being about both Da vinci and Picasso.

• #### dojibear

##### Senior Member
Can students conclude from this that the teacher has excluded the possibility of the question being about both Da vinci and Picasso.
No.

In mathematics (and computer software) there are two kinds of "or" operation:
- inclusive OR ( A, B, A+B)
- exclusive OR ( A, B, but not A+B)

English "or" does not make that distinction. There is no way to know the teacher's meaning.

#### CaptainZero

##### Senior Member
I can't see it that way, dojibear.
Can students conclude from this that the teacher has excluded the possibility of the question being about both Da vinci and Picasso.

#### kentix

##### Senior Member
Me, too. One question can only be about one person as described that way.

#### Robby Zhu

##### Senior Member
I guess, logically, the sentence doesn't exclude that possibility, but as used in everyday speech, it could implicate the question won't be about both, right？

#### dojibear

##### Senior Member
The question in part 2 will be about Da vinci or Picasso.
Yes. This implies one or the other, not both

#### entangledbank

##### Senior Member
Yes, the word 'or' doesn't exclude 'and', but we know how teachers warn their students: you will have to study both X and Y, because one of them will be on the test, but I'm not telling you which one. So in this situation, and many others, we naturally read it as exclusive.

I think it would be hard to devise a realistic situation where it was actually doubtful. (The classic example is 'Would you like tea or coffee?', which is only doubtful in print: in speech the intonation clearly distinguishes the two meanings.)

#### Hulalessar

##### Senior Member
English "or" does not make that distinction. There is no way to know the teacher's meaning.
In many cases it has to come down to pragmatics. In the case quoted there can be little doubt that the question will be either on da Vinci or Picasso and not on both.

Not a few law cases have turned on whether in a particular case an "or" is conjunctive or disjunctive - and for that matter whether "and" is conjunctive or disjunctive. For anyone who has the time and inclination to read it here is an article on the question: https://digitalcommons.wcl.american.edu/cgi/viewcontent.cgi?article=2030&context=facsch_lawrev