The direct form of Martha's warning to Toby is: 'Martha warned Toby that she would never know who broke the window unless somebody said something.' This is transforming the given indirect speech to direct speech.
The direct form of the indirect statement: 'Martha warned Toby, "She'll never know who broke the window unless somebody says something."' can be translated to: 'Martha warned Toby that she would never know who broke the window unless somebody said something.'
Direct and indirect speech are used in English to express the content of statements, questions, or other utterances. In direct speech, the original speaker's exact words are repeated. Indirect speech, on the other hand, uses third person forms and changes the tenses of the words spoken.
In conclusion, the correct direct form of the statement is: 'Martha warned Toby that she would never know who broke the window unless somebody said something.'
Learn more about Direct and Indirect Speech