The present, in three ways

The cherry tree story used three past tenses. This story uses three present tenses.

1. Simple present: a fact, a habit, or something generally true.

• 'It is hard not to be able to work.'
• 'I am too old.'
• 'Ravi practises crop rotation.'

2. Present progressive (am/is/are + -ing): something happening now, often for a short time.

• 'What are you smiling at, Amma?'
• 'That is what I am talking about.'
• 'This year he is growing legumes' (just this year).

3. Present perfect (have/has + past participle): something that began in the past and still matters now.

• 'I have worked hard and honestly.'
• 'The earth has worked for years, centuries, in fact, thousands of years.'

That last sentence is the whole story in one tense. 'The earth worked' would mean it is finished. 'Has worked' means it is still working, and so still tired.

And Velu's 'I have worked hard' uses the same tense as the earth's 'has worked'. The old woman wants him to see that both of them are tired workers.

The Ravi passage:

• 'Ravi is a farmer who practises crop rotation.' (facts)
• 'Each season he plants different crops.' (habit)
• 'This year he is growing legumes.' (now, for a while)
• 'Over the years Ravi has learnt that planting the same crop again and again depletes the soil.'
• 'He has seen a clear improvement since adopting this method.' ('since' signals the present perfect: from a past start until now)
• 'Now Ravi is sharing his knowledge.'