Perspicacious is an adjective that characterizes the person able to easily understand something that others cannot, meaning that you are smart, intelligent and shrewd.
One insightful person is the one that acts with insight, this means that you have a very high level of perception to be able to understand things quickly.
Example:"Thanks to your shrewd reasoning we were able to solve the riddle".
The quality of acumen is typical of people considered intelligent or smart, as it requires a advanced sense of analysis and interpretation of situations, so that a quick understanding of the subject is concluded.
Not all people, however, can be classified as insightful. However, being insightful is not directly related to the level of education or knowledge that the person has.
Among some of the main synonyms for insightful, stand out: cunning, smart, shrewd, intelligent, deep, sharp, penetrating and clear.
See also:meaning of cunning.
The word insightful can still be used to refer to someone who can see far, that is, who sees very well.
In English, the term insightful can be literally translated to perceptible or shrewd, while insight as shrewdness or perspicacity, for example.