Question

Complete the sentence using could/couldn't/can/can't with the given verb:
My grandfather was a very clever man. He ____ (speak) five languages.

• A. could speak
  
• B. couldn't speak
  
• C. can speak
  
• D. can't speak
  

Answer 1

Answer: (A)

could speak

'Can' indicates ability/capacity.
'Could' is used as the past tense of 'can'.
'Can't' indicates present incapability/impossibility.
'Couldn't' indicates past inability.
Here, the speaker refers to the past ability of his/her grandfather. Therefore, the correct option is: A) could speak.