Circumstantials and their ordering in discourse
There is a strong tendency to add circumstantial information, even when it is not strictly required by syntactic or semantic criteria for a single clause, one reason being that it is often crucial to the development of the discourse. So, rather than saying Tom disappeared, we might add an optional circumstantial such as among the crowd, into the Underground or below the surface of the lake.
Even more clearly, the conditional clause adjunct – as in If you don’t learn, you’re not much good as a teacher – is necessary for a full understanding of the speaker’s intended meaning. Without it, the message is very different. Conversely, with verbs such as leave, arrive and go, Source, Goal and Location adjuncts are omitted if they are contextually understood (haven’t they left/arrived/gone yet?).
When a number of circumstantials cluster at the end of a clause, they tend to be placed in certain semantic orderings, such as Source-Extent-Path-Goal. This is partly illustrated in this slightly adapted sentence from a report. We can see that ‘Source’ does not figure, while ‘Purpose’ does. Manner of movement is realized by the verb.
