In the Latin language, verbs take one of four conjugations. The first grouping, the first conjugation, can be distinguished from the other conjugations by using -a type endings in the indicative mood and -e type endings in the subjunctive mood.
Consider habito, habitare, habitavi, habitatus to inhabit
The infinitive form can be parsed into habit/a/re, with habit- being the general stem, -a- the indicative "letter" for first conjugation, and -re being the usual ending for present active infinitives. Hence the present active indicative is conjugated:
Singular
1st ..... habito
2nd ..... habitas
3rd ..... habitat
Plural
1st ..... habitamus
2nd ..... habitatis
3rd ..... habitant
Most 1st conjugation verbs follow this pattern in the indicative. Subjunctives are formed with indicator -e-. The present active subjunctive of habito, -are is:
Singular
1st ... habitem
2nd ... habites
3rd ... habitet
Plural
1st ... habitemus
2nd ... habitetis
3rd ... habitent
Perfect passive voice is formed in the common manner of affixing a form of sum, esse, fui, futurus to be to the supine. The supine must agree with the subject of the sentence in gender, case, and number. The present perfect passive indicative and subjunctive of habito, -are, in the form of a male subject:
Singular where x/y x is indicative, y is subjunctive
1st ... habitatus sum/sim
2nd ... habitatus es/sis
3rd ... habitatus est/sit
Plural
1st ... habitatus sumus/simus
2nd ... habitatus estis/sitis
3rd ... habitatus sunt/sint
I have not the space here to create a synopsis of each form in the first conjugation. Yet the most difficult part of any conjugation in Latin is determining which conjugational letter (-a or -e) appears for indicative or subjunctive, and applying this knowledge to the various endings in each tense. | 
