What language did Lewis and Clark speak?

Answer 1

Lewis and Clark spoke regularly spoke English.

Lewis would speak English to Private Francois Labiche, who would speak French to the interpreter Toussaint Charbonneau, who would speak Hidatsa to his Shoshone wife Sacajawea, who would speak Shoshone to Chief Cameahwait.

Answer 2

Lewis and Clark primarily spoke English, as they were both American explorers. They also interacted with various Native American tribes during their expedition and likely used interpreters to communicate in different languages.