This is the 118th most frequent Tamil word.
நன
The Tamil word "நன" translates to "goodness" or "benefit" in English.
Here, 'நன்' is used as a root in the adverb 'நன்கு', meaning 'well', which qualifies the activity of studying.
நன்கு படிக்க வேண்டும்.
One must study well.
In this sentence, the variant 'நல்' is used as an adjective meaning 'good', describing the teacher.
நல் ஆசிரியை உங்களை சந்தித்தார்.
A good teacher met you.
In this sentence, 'நன்' is used as the root in 'நன்மை', a noun meaning 'goodness', referring to virtuous acts.