Analysing everyday conversation 139Transactions
Exchanges combine to form transactions: each exchange realizes one element
of transaction structure. As the table on pp. 125–7 shows, the transaction
has only one obligatory element of structure—M—which is realized by one
exchange. As the notation (M^2 ...Mn) indicates, each subsequent exchange
realizes M^2 , M^3 , M^4 , etc.—there is no upper limit. Most transactions consist
of several exchanges realizing Ms.
The other two elements of structure—P and T—are optional. When
P or T occurs, it is realized by one or more of the units comprising the
Organizational class of exchange—Boundary, Structuring, Greet and
Summon. M is realized by one of the units comprising the Conversational
class of exchange—Elicit, Inform, Direct, and the three bound-Elicit
exchanges.
In the absence of an exchange (or exchanges) realizing P, there is a
further way in which the beginning of a new transaction may be recognized,
and that is by intonation. When a participant selects high key and proclaiming
tone for the first tone unit of an utterance, the utterance is seen as transaction-
initial. An example of this occurs in exchange (124) of our data sample (see