What is the difference between the Simple aspect and the Perfect aspect?
Background: It says: "The simple aspect does not tell us whether action is ongoing or complete as it does not contain either the progressive or perfective aspects."
However, from the following example, I can make out that the action was completed. Example: We climbed Mount Kilimanjaro.
On the other hand, the perfect aspect is not that confusing.
Example: We have climbed Mount Kilimanjaro twice as of today. Example: He has finished his homework just now. (both are completed actions in reference to the present)