1- I do think that nonhumans can communicate. In the article Vocal responsiveness in male wild chimpanzees: implications for the evolution of language the author explores how chimpanzees communicate by learning symbols. I think that we often think of a language as something that is spoken but there are other ways to communicate with other species. According to the observations of Arcadi chimpanzees can communicate vocally but it is at a low rate only when it needs to be done.
2- Intelligence is the ability to acquire and apply knowledge that is acquired. An example would be a student who takes extensive notes in a difficult class and studies and is apple to apply the material that they learn. For example a law student has to be able to apply all information learned in their classes to pass the Bar Exam and use that knowledge as they practice law.
Arcadi, A. C. (August 01, 2000). Vocal responsiveness in male wild chimpanzees: implications for the evolution of language. Journal of Human Evolution, 39, 2, 205-224.
Intelligence. (2017, October 30). Retrieved November 08, 2017