This is basically due to the fact that the English tense forms express certain concepts of time and aspects of verbal actions that are not expressed by means of verbal forms in many other languages.

The choice of the tense form in English depends in most cases on whether you see the action as something complete (simple form) or in progress (progressive form), as timeless (Present Simple) or limited in time (Present Progressive), whether the focus is laid on the activity or on the result of the activity, etc.