Some categorise the perfect forms (present perfect, past perfect) and the continuous forms (present continuous, past continuous) as aspects. Aspects describe how an event or state expressed by a verb extends over time.
By this analysis there are two tenses present and past (aka preterite), and four aspects: simple (or neutral), perfect, continuous (or progressive), and perfect continuous. These could be arranged as follows
||I have eaten
||I had eaten
||I am eating
||I was eating
||I have been eating
||I had been eating
English, you will note, expresses aspects by the use of auxiliary verbs with a participle in a subordinate position.
But while English separates the aspects from tenses, the meaning of the aspects overlaps with tenses. So, for example, in many situations the same idea can be expressed with past tense or with present perfect.
Subjunctive doesn't exist as a verb form in English, it is a type of clause.