Grammar-Quizzes › Verb Phrases › Verb Groups › Modals › Can vs. Could
PHYSICAL ABILITY | |
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|
|
CAN / COULD | PLAIN FORM VERB |
"Watson", a super computer, can |
answer questions in "natural language". |
Watson can |
access 200 million pages of information in seconds. |
Watson cannot |
think like a human. It can only learn. |
In most cases, the computer could |
win. (come up with correct answers first) |
MENTAL ABILITY | |
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|
|
CAN / COULD | PLAIN FORM VERB |
Ken Jennings can |
speak on a wide variety of subjects. |
Ken can |
play a game to win. |
Ken could |
outsmart his opponents every time. |
Often, Ken could |
outsmart Watson's reasoning ability. |
Watson is an artificial intelligence computer system capable of answering questions posed in natural language, developed by IBM. http://en.wikipedia.org/wiki/Watson_(computer)
Jeopardy – a game show in which contestants are give the answer and must come up with the question
Also see May / Can (permission)
REACHED A GOAL | |
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|
|
WAS / WERE ABLE | INFINITIVAL VERB FORM |
IBM engineers were able |
to design a computer that uses "natural language". |
After several tries, IBM engineers were able |
to program Watson to win a match. |
Ken Jennings was able to |
win 75 Jeopardy matches. |
Watson was not able |
to understand his opponent's answers. |
POTENTIAL | |
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|
|
CAN / COULD | PLAIN FORM VERB |
In the future, Watson can |
help suggest treatment options to doctors. |
Watson can |
analyze a patient's symptoms and medical history. |
Ken Jennings can |
use his celebrity to endorse products. |
One day, IBM could |
build a computer with cognitive power. |
cognitive (Adj) – having mental processes of perception, memory, judgment, and reasoning,
contestant (N) – person playing or competing in a game or competition
opponent (N) – the person you play against in a game.
COULD – GENERAL ABILITY |
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|
MULTIPLE PAST EVENTS OR ONGOING |
I practiced a lot during the winter. By summer, I could drive pretty well. (general timing) If I wanted to, I could drive to work or to the store. |
Before 1935, anyone could drive. Now the state requires a license. Only state residents could apply for a driver's license.
|
WAS ABLE – PAST ABILITY |
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|
SINGLE PAST EVENT – MOMENT OF COMPLETION |
I practiced a lot during the winter. By summer, I was able to pass my driving exam. By summer, I could pass my driving exam. (single event) |
I was able to get my driver's license. I managed to get my driver's license. I succeeded in getting my driver's license. |
Eng-US: license (n./ v.) , Eng–Br: licence (N); Eng-US: practice (n./ v.); Eng–Br: practise (V)
Pop-Q Resultive "so".
MODAL | SUBJECT | MODAL / VERB EXPRESSION | MAIN VERB | OBJECT PHRASE |
---|---|---|---|---|
STATEMENT | ||||
|
Jack |
can |
cook |
dinner. |
Jack |
is able to |
fix |
your bicycle. |
|
Jack |
knows how to |
use |
a computer. |
|
QUESTION | ||||
What can |
Jack |
|
do? |
|
Can |
Jack |
|
lift |
that computer by himself? |
Is |
Jack |
able to |
drive |
your car? |
Does |
Jack |
know how to |
use |
a computer? |
NEGATIVE | ||||
Jack |
can't |
come |
home early. |
|
Jack |
is not able to |
come |
home early. |
|
Jack |
doesn't know how to |
come |
home early. |
|
PAST | ||||
Jack |
could |
stay up |
all night when I was 18. |
|
Jack |
was able to |
stay up |
all night on New Years. |
|
|
Jack |
knew how to |
use |
a computer |
WTH AN ADVERB | ||||
Jack |
can usually / usually can |
cook |
dinner in an hour. |
|
Jack |
is sometimes able to |
do |
his homework. |
|
|
Jack |
always knows how to |
fix |
a computer problem. |
W/ NEG. ADVERB | ||||
*Seldom can |
Jack |
|
get |
his homework done. |
TRADITIONAL & ESL DESCRIPTION | LINGUISTIC DESCRIPTION |
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AZAR | HUDDLESTON |
can / could (Azar 10.1-4)
|
can / could "Mood and Modality" (Huddleston 3 §9)
|
SWAN | BIBER |
can/ could (Swan 122-5)
|
can / could (Biber 6.6.4.1) permission / possibility / ability: can, could Could and might are much more common expressing logical possibility than permission or ability. In contrast to the typical functions of can, the modal could usually marks logical possibility in conversation, expressing a greater degree of uncertainty or tentativeness. That could be her. It could be anything you choose. Epistemic Stance.modal Verb in extrinsic sense → Without… collaboration there could be interference… (973) |