Research has shown that natural language communication is more effective than intention-signaling in promoting coordination. Our paper studies the reasons behind this finding. We hypothesize that, when communicating with natural language, people use and respond to both intentions and attitudes, with attitude indicating the strength of a message sender’s desire to have her message followed. We test our hypothesis using controlled laboratory experiments. We find that: (i) free-form messages include both signaled intentions and attitudes; (ii) people respond to both intentions and attitudes when making decisions; and (iii) the use of attitude in natural language messages significantly improves coordination.