These three do all the work that English spreads across at, in, on, to, into, towards and from. Learning them separately, months apart, is how people stay muddled. They are one system.
Di means nothing is moving. Ke means movement towards. Dari means movement away, or where something started.
The same sentence, three times
Saya di Bali. ‘I’m in Bali.’
Saya ke Bali. ‘I’m going to Bali.’
Saya dari Bali. ‘I’m from Bali.’
Same words either side. Only the marker changes, and it changes everything.
The three questions
You already met di mana. It has two siblings, built the same way.
Di mana? ‘Where?’, as in where is it.
Ke mana? ‘Where to?’
Dari mana? ‘Where from?’
Mau ke mana? ‘Where are you going?’ is probably the single question you will hear most often in Indonesia. It is small talk, not interrogation.
No word needed for in, on or at
English chooses between at the market, in the house, on the table. Indonesian uses di for all three and lets the noun carry the rest.
di pasar ‘at the market’
di rumah ‘at home, in the house’
di meja ‘on the table’
If you genuinely need to be precise, you add a position word: di atas meja ‘on top of the table’, di dalam rumah ‘inside the house’. Most of the time you do not.
Here and there
di sini ‘here’
ke sini ‘to here, come here’
dari sini ‘from here’
And the same with sana ‘there’. The pattern holds without exception, which makes this one of the tidiest corners of the language.
The mistake to expect
English speakers reach for di when movement is involved, because “I’m at the market” and “I’m going to the market” both feel like statements about the market.
Saya ke pasar. ‘I’m going to the market.’
Saya di pasar. ‘I’m at the market.’
Say the second when you meant the first and you have told someone you are already there.