言语 is more literary/formal than 话 (huà) or 说话 (shuōhuà). It often appears in written Chinese or formal speech. In everyday conversation, people say 说话 or just 话.
usage
The character 言 is also the speech radical (讠 in simplified) that appears in many language-related characters: 语, 说, 话, 词, 读, 请, etc.
