Fill in the blank with the correct modal:

I ________ swim across the river when I was young.

(A) should
(B) ought
(C) may
(D) could

Choose the correct answer from the options given below :

(D) Only

The correct answer is Option (2) - (D) Only

The sentence refers to an ability the speaker had in the past. The correct modal verb to express past ability is "could."

• (A) Should: Incorrect because "should" expresses obligation or advice, not past ability.
• (B) Ought: Incorrect because "ought" also expresses moral obligation, not ability.
• (C) May: Incorrect because "may" indicates possibility or permission, not past ability.
• (D) Could: Correct because it denotes an ability the speaker had in the past.

I ___could_____ swim across the river when I was young.