In English grammar, the term "tense" traditionally refers to any conjugated form
expressing grammatical tense, aspect, or mood. The large number of different composite
verb forms means that English has the richest and subtlest system of tense and
aspect of any Germanic language. This can be confusing for foreign learners;
however, the English system can be presented systematically by noting that each
of the temporal spheres (past, present, future) distinguishes simple forms from
progressive (continuous), perfect, or both.