The law says that all public buildings must be accessible to people who have trouble _____. A. walki

The law says that all public buildings must be accessible to people who have trouble _____. A. walking B. walk C. to walk D. walked

The correct answer is A. walking. The phrase "have trouble" requires a gerund (-ing form) as its object, following the grammatical pattern "have trouble + V-ing". This structure is used to express difficulty in performing an action.

Other options are grammatically incorrect:

B. walk (base verb) and C. to walk (infinitive) do not fit the "have trouble + V-ing" pattern.

D. walked (past participle) would imply passive action, which is illogical here.

Why does English use gerunds after "trouble"? This pattern likely evolved because "trouble" describes an ongoing challenge, which aligns with the dynamic nature of -ing verbs. Similar structures include "have difficulty walking" or "struggle walking". Can you think of other verbs that require gerunds after them?