Adjuncts have traditionally been analysed as being of one of two types:
restrictive adjuncts
and operator adjuncts. Restrictive adjuncts are adjuncts which
``restrict'' the value of a particular index representing
an object, event, or situation, such as the index for location or time
of the event. These adjuncts specify properties to be associated with
the indices. Operator adjuncts are adjuncts which take the content of
what they modify as an argument in a semantic operation, predicating
something of that content. Examples of this type of adjunct include
negatives, frequentatives, and duratives.
The distinction between these adjunct types provides an explanation of the differences in the semantics of (3.61a) and (3.61b), containing operator adjuncts, as compared to the lack of semantic difference between (3.62a) and (3.62b), containing restrictive adjuncts. In (3.61a), the twenty minute duration is a property of the event whose frequency is described, while in (3.61b), the `twice-dailiness' is a property of the event whose duration is described (Pollard and Sag 1987). In both (3.62a) and (3.62b), in the park specifies the location of the jogging, and yesterday specifies the time of the jogging, regardless of their surface order. They each specify (or restrict) properties of the main event described in the sentence, rather than predicating something of an event they receive as an argument, as in d46. (Sentences from P&S 1987, (252))
John jogged for twenty minutes twice a day. John jogged twice a day for twenty years.
John jogged in the park yesterday. John jogged yesterday in the park.
In essence, restrictive adjuncts seem to add new information about an index for which the event was previously underspecified (e.g. location) while operator adjuncts take the event as an argument, thereby building up a more complexly structured semantic representation for the sentence.
There is a group of adjuncts which semantically do not clearly fit either of these two types. These adjuncts, like all other adjuncts, add information to the basic event expressed by the verb plus its semantic arguments. However, they do not simply restrict an index specifying something about the situation in which the event occurs or predicate something of that situation. Rather, they relate information via one of a predetermined, limited, set of subordinating relations. They can be viewed as adding a theme to the verb semantics, and thus will be called thematic adjuncts. Examples of thematic adjuncts can be found in d82-d84. In d82, the because_of-PP adds information which explains the cause of the situation expressed in the remainder of the sentence. In d83, the with-PP expresses the means by which the situation expressed in the sentence minus the PP occurred. In d84, the to-PP expresses a motivation for the situation in the remainder of the sentence.
Peter reads well because of the tutoring. [Kasper 1993, (10a)] Peter opened the door with the key. Peter read the book to learn about World War II.