Delahunty and Garvey
The relevant time span can also be interpreted as shortly before the refer-
ence time, or recently:
(76) I had (just) finished another paper by then.
(77) Have you seen my spectacles (recently)?
Exercise
- Using the discussion just above, identify what is implied by the use
of the perfect in each of the following sentences.
a. Mary has played tennis for seventeen years.
b. Mary has played tennis.
c. Mary has just played tennis.
d. Martin has given a Groundhog Day party for 17 years. - Why is the following interchange odd?
Zeke: Have you cooked dinner?
Clem: Yes, about ten years ago.
(What happens if you add ever or yet to Zeke’s question?) - The following is an extract from a Scientific American article by Rob
Dunn, (December 2007: 46) on the surprising speed at which evolution
can occur. (a) Identify all the instances of the perfect aspect in the pas-
sage. You should find that almost all the sentences in the passage are
in the perfect. (b) What is the tense of each perfect clause? (c) Why do
you think the author chose the perfect aspect as basic for this piece?
To help with this last question you might try re-writing the passage
without using the perfect, for example, in the simple past tense, and
comparing the two versions.
We see rapid evolution most often where some force (often us)
has given it a jump start by suddenly and dramatically altering an
organism’s environment. Rats have developed smaller bodies when
introduced to islands. Trophy fish have also adopted smaller body
sizes in response to fishers’ preference for big fish (which, if killed, do
not breed). Mayflies in streams where trout were released now forage
at night to avoid the fast-swimming predators. Many hundreds of
herbivorous species have switched to novel, sometimes toxic, food
sources introduced by humans and have come to specialize in con-
suming those new resources. Various native species have evolved in