There are several ways of expressing the future in English, including the use of:
- the simple present: We leave tonight for Atlanta.
- the present progressive: We're leaving the kids with Louise.
- the modal verb will (or shall) with the base form of a verb: I'll leave you some money.
- a semi-auxiliary such as to be going to or to be about to: We are going to leave your father a note.
For the complete article (revised and expanded), see Does the English Language Have a Future Tense?