Page 91 - English - Teaching Academic Esl Writing

SENTENCES, PHRASES, AND TEXT CONSTRUCTION 77
tense/time in which to use verbs in a particular context is the first step, fol- lowed by marking the verb for a particular tense (see chap. 7).
The tense can be marked (e.g., talks., talked., goes., went) or unmarked (e.g., I/we/you/they talk/go). Once the tense of the verb is determined, it creates a domino effect in the rest of the verb phrase elements.
Another important element of the verb system is aspect, such as progres- sive and/or perfect, both of which require auxiliaries:
issinging [progressive];hassung [perfect];hasbeensinging [perfectprogressive]
were eating [progressive]; had eaten [perfect]; had been eating [perfect progressive]
In the case of the progressive verb, the order of the verb phrase elements is as follows:
be
present -> am/is
I am/ He is
+ the base form of + -ing the main verb
+ sing + -ing singing.
Similarly, in the case of the perfect aspect, the auxiliary have is followed by the past participle form of the main verb:
have + past participle present -> have/has + spoken/eaten
In addition, perfect and progressive aspects can occur together in the present perfect progressive (e.g., have/has been speaking) or the past perfect progressive (had been singing). A quick overview of auxiliary verbs with a few tense and aspect combinations can be:
am/is/was have/had has/had been
sing+ing/cook+ing talked/spoken talking/speaking
[BE + base verb + -ing]
[HAVE + past participle]
[HAVE + BE-en (past participle) + base verb + -ing)
To combine the various elements of the verb phrase, such as the tense, modals, and other auxiliaries, a slot system can be created specifically tai- lored toward the regularities in the verb system:
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