4-Mercy at Appomat I. Wordstudy In negative statements doubt is followed by that. I dont doubt that he's telling the truth. In other statements doubt is often followed by if or that, though some people feel whether is the only correct form here: I doubt whether he's telling the truth. WBTLE BACW B T L E I. Word Study In negative statements doubt is followed by that: • I don’t doubt that he’s telling the truth. In other statements doubt is often followed by if or that, though some people feel whether is the only correct form here: • I doubt whether he’s telling the truth. Lesson 14 – Mercy at Appomattox