could

• aux.できる
• v. able（canの過去形）

can、canから。-d、過去分詞接尾辞。

could

could: [16] Could began life as cūthe, the past tense of Old English cunnan ‘can’. By Middle English times this had become couthe, and in the 14th century it developed to coude under the influence of the standard past tense ending (e)de. The l was introduced in the 16th century, to bring coude into line with would and should.
=> kith, uncouth

could (v.)

Old English cuee, past tense of cunnan "to be able" (see can (v.1)); ending changed 14c. to standard English -d(e). The excrescent -l- was added 15c.-16c. on model of would, should, where it is historical.

1. He could just about see the little man behind the counter.

彼はカウンターの後ろにいる小柄な男をかろうじて見ることができた。

2.So,if we could just move onto something else？

では、他の話をしてもいいですか。

3.Northbridge is a cool，calculating and clever criminal who could strike again.

ノーズブリッジは冷静で悪巧みが多く陰険で狡猾な犯罪者で、彼はまた犯罪を犯すかもしれない。

4.It was feared they could break the Allies 'codes.

連合軍の暗号を解読する恐れがある。

5.Politicians say it could lead to a disolution of parliament.

政治家たちは、議会解散につながる可能性があると言っている。