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Table 1: Experimental Results.
first test second test
(no asking back questions) (asking back questions)
past tense present perfect tense past tense present perfect tense
(problem 1) 8 0 7 1
(problem 2) 8 0 7 1
(problem 3) 7 1 0 8
(problem 4) 7 1 1 7
explanation “predicate verb (past tense)” is the past
action or event. Please use the verb in the past
tense when you translate this sentence into En-
glish.
example kinou (yesterday), shukudai ga (homework)
owatta (finished).
I finished my homework yesterday.
(a) The explanation and example which our system gives to
the user when he/she determines that there is no connec-
tion between the past and the present.
explanation “predicate verb (past tense)” is the past
action or event which is connected with the
present in some way. Please use the verb in the
present perfect tense when you translate this sen-
tence into English. However, you do not use
the present perfect tense when the sentence in-
cludes adverbs of finishing time (like yesterday,
last week, in 1990, etc).
example mou (already) shukudai ha (homework)
owatta (finished).
I have already finished my homework.
(b) The explanation and example which our system gives to
the user when he/she determines that there is some con-
nection between the past and the present.
Figure 5: Examples of explanations and example sentences
generated according to user’s determination of the presence
of connection between the past and the present. In fact, ex-
planations are written in Japanese and “predicate verb (past
tense)” is replaced by a predicate verb (past tense) extracted
from an input sentence.
In (problem 1) and (problem 2), the suitable tenses
were past tenses. On the other hand, in (problem
3) and (problem 4), the suitable tenses were present
perfect tenses. In this experiment, we conducted two
tests. In the first test, our system did not give asking
back questions to the students. We examined whether
the students could select suitable tenses without the
support of our system. In the second test, our sys-
tem gave asking back questions to the students. We
examined whether the students could select suitable
tenses by using asking back questions. Table 1 shows
the experimental results. In Table 1, underlined num-
bers show the numbers of students who select the suit-
able tense. As shown in Table 1, in the first test,
the students mainly used past tenses. The result of
the first test shows that Japanese speakers often mis-
takenly use the past tense in English sentences when
they should use the present perfect tense. On the other
hand, the result of the second test shows our method
is useful to help users to select suitable tenses in En-
glish sentences. However, two students mistakenly
determined that present perfect tenses were suitable
for (problem 1) and (problem 2) in the second test.
In the first test, they correctly determined that past
tenses were suitable for (problem 1) and (problem 2).
We interviewedthese two students and found that they
did not know we do not use the present perfect tense
with adverbs of finished time. To reduce these fail-
ures, we are considering adding new explanation to
asking back questions: we do not use the present per-
fect tense with adverbs of finished time (yesterday,
two hours ago, etc.).
In order to talk about the past, we use six different
tenses in English sentences:
• past tense (I worked),
• past progressive tense (I was working),
• present perfect tense (I have worked),
• present perfect progressive tense (I have been
working),
• past perfect tense (I had worked), and
• past perfect progressive tense (I had been work-
ing).
In this study, we dealt with only two of them: the past
tense and the present perfect tense. We will examine
whether our asking back method is useful when other
kinds of tenses are suitable for the given sentences.
REFERENCES
Oshika, Satou, Ando, and Yamana: An English Com-
position Support System using Google, IEICE
DEWS2005, (2005).
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