Present tense is a verb form which is marked by time (tense).
The present tense is used for actions in a time which is happening now. In order to explain and understand present tense, it is useful to imagine time as a line on which the past tense, the present and the future tense are positioned. The use of present continuous tense: a. For something which happening at the same time of speaking b. For something which happening at around the time of speaking but not necessarily exactly at the time of speaking c. For something which happening at period around the present (today, this season)
- Sangmeister, Lisa. (2009). Past Tense in English: From OE to PDE, p. 11.