Overview

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These notes aim to get a better handle on the syntax and semantics of coordinators, like and and or. Something special about coordinators, at least in English, is that (at least, apparently) they can coordinate expressions of any category. For example, while we can coordinate sentences and verb phrases, as in (1)

1. 1. Po slept {and, or} Tigress jumped.
   2. Po slept {and, or} jumped.

we can also coordinate noun phrases, transitive verbs, prepositional phrases, and perhaps even other categories like prepositions, as in (2).

2. 1. Po {and, or} Tigress slept.
   2. Tigress punched {and, or} helped Po.
   3. Po cooked noodles in the kitchen {and, or} for Tigress.
   4. Po cooked noodles inside {and, or} outside the kitchen.

Not only is it possible to coordinate strings of various categories, but when we do, a systematic pattern of inference arises. Specifically: when we coordinate constituents smaller than sentences, what’s produced is a sentence which seems to mean the same thing as a sentence-level coordination. For example, the sentences in (2) appear to mean the same things as the sentences in (3), respectively, when the same coordinator occurs in both.

3. 1. Po slept {and, or} Tigress slept.
   2. Tigress punched Po {and, or} Tigress helped Po.
   3. Po cooked noodles in the kitchen {and, or} Po cooked noodles for Tigress.
   4. Po cooked noodles inside the kitchen {and, or} Po cooked noodles outside the kitchen.

In each case, the (2) sentence entails the (3) sentence, and vice versa. How can we explain this?