Choose from the options how the sentence can be improved:
They only work when they have no money.

The correct answer is '3'.

Key Points       

• The original sentence contains an ambiguity due to the placement of the adverb "only." The word "only" should ideally be placed immediately before the word or phrase it modifies for clarity.       
• In "They only work when they have no money," "only work" can ambiguously mean either:
  • They do *nothing but work* when they have no money (i.e., it's their sole activity).
  • They *work exclusively when* they have no money (i.e., their working is restricted to that condition).       
• To convey the more common and precise meaning (that their working is restricted to the condition of having no money), "only" should modify the clause "when they have no money."

Corrected sentence: They work only when they have no money.

Additional Information  

• Option 1: "When they have no money, they only work."                               
  • While the initial placement of the 'when' clause is fine, the ambiguity of "only work" remains. This structure still suggests that 'working' is the *sole* activity they do.            
• Option 2: "they only work"                               
  • This is an incomplete phrase and does not offer a complete sentence improvement.              
• Option 4: "No improvement"                               
  • This is incorrect because the original sentence contains an ambiguity that can be improved for clarity and precision.