Verbs
1. Agreement with subject or object or inclusion of a subject or object pronoun.
2. Time and aspect of the action.
3. Voice, e.g. transitive, intransitive, active, and passive.
4. Mode (the psychological background of the action as represented by the speaker), e.g. indicative, optative, conditional, interrogative, and potential. - Nida (1949), a pag.149