Select the most appropriate option to improve the underlined segment in the given sentence. If there is no need to improve it, select ‘No improvement’.

I wish I know how to play the guitar. 

The correct answer is- I knew.

Key Points​

• ​Conditional sentences are statements discussing known factors or hypothetical situations and their consequences.
• One of the structures is mentioned below:
• This particular type is followed when we talk about something in the past which is purely imaginary.
  • If + Simple Past, Subject + Would + V1 + Object.
• Example:
  • If I had wings, I would fly like a bird.
• In the underlined part of the given question, 'knew' will be used as per the rule given above.
   

Correct Sentence: I wish I knew how to play the guitar. 

 ​​​​Additional Information  ​

• There is one more type of conditional sentences in the past tense given below:
• This particular type is followed when something didn't happen as a certain condition wasn't fulfilled.
  • If + Subject + had + V3 + object, Subject + Would have + V3 + Object.
• For example:
  • If I had noticed you, I would had call you.
  • If I had noticed you, I would have called you.