Symbols are objects or actions that are included in a text in order to convey something deeper or more varied than their literal meaning. A symbol can create suspense because of its repetition. When a symbol appears several times in a text, it can affect the mood of a text. Moreover, it can foreshadow future events that the reader anticipates.
An example of a symbol is the skull that appears in Hamlet. On the one hand, this object is simply Yorick's skull. However, on a different level, the skull is a symbol that represents mortality. The presence of the skull leads Hamlet to ponder about his own mortality, and it increases the suspense in the reader.