A முற்று that only shows gender and person, leaving the tense implied rather than stated - built from any of the 6 பெயர்ச்சொல் types (பொருள், இடம், காலம், சினை, பண்பு, தொழில்).

Introducing someone as நல்லவன் tells you gender and person immediately, but leaves you to infer from context whether it's always true or just true now.

அவன் நல்லவன் - "he is good", no explicit tense marker.