Although you can type expressions on your own, you can also use Expression Builder to help you construct them.
You use Expression Builder in Design view. In the query design grid, right-click the cell where you want to create an expression, such as a field's Criteria cell, and then click Build on the shortcut menu.
If you know the syntax of the needed expression, you'll probably want to type it yourself in the query design grid. However, you may find Expression Builder useful if you don't know the syntax of an expression you want to create. You can also use it to create the basic structure, and then make any refinements by typing.
Note You can also use Expression Builder to create calculated fields, which you'll learn about in the next lesson.