That's a terrific question that is quite complicated to answer and remains an ongoing research area. Current research suggests that babies are born with the capacity to think about objects before developing language to describe these objects. However, the specific language that we think in may influence the way we experience, or at least describe, the world around us. Because languages vary, this can influence how people speaking different languages may perceive their world. Researchers are also interested in understanding how animals other than humans think, since no other species has a language system like our own.