The pilot ran at one of only two organisations approved to teach Hindi as a Mother Tongue Language within Singapore's Ministry of Education framework — a long-established weekend Hindi school with over 3,000 enrolled students across its centres. The cohort for this pilot was a single Primary 3 group (children aged 8–9).
The cohort is a clean test of the heritage-learner profile: children who hear Hindi at home, are taught it formally once a week, and live the rest of their lives in a non-Hindi-dominant environment — in this case, English and Mandarin.
When it comes to Hindi for diaspora children the gap is rarely teaching — good weekend schools teach well. The gap is practice: a child gets two hours of Hindi on a Saturday and then lives the other six days almost entirely in English, and by the next Saturday much of it has decayed. Hindi Tutor exists to fill those six days — to be the daily speaking-practice layer that keeps a child's Hindi alive between classes.
Primary 3 (ages 8–9) is the hinge year. The children are old enough to hold a real conversation and form complete sentences — which is what makes their speech measurable at all — and young enough that the slide into English-only replies has only just begun, so a daily habit can still take root. They can also drive a voice interface on their own, without a parent steering every turn.
These are P3 children inside one of Singapore's MOE-recognised Hindi Mother-Tongue programmes — a relatively strong, formally-taught foundation. The Hindi on display here is what well-taught heritage 8–9-year-olds sound like. The more telling signal for a school is what happens at the other end of the same cohort: the children who arrived weak, or with no one at home to practise with — covered further down.
No teaching method or curriculum fixes the six days between Saturdays. So the pilot tested one narrow, honest question:
To make the answer meaningful, it was run under near-worst-case conditions on purpose:
The only contact was two emails from the school inviting families to register. Whatever engagement followed had to come from the child wanting to return.
The signal is the shape: the big loss is at registration, before the product is ever experienced. Of the 28 children who began a conversation, 25 came back for three or more. The leak is at the door, not inside the room.
Families who never registered. The product never had a chance to reach them — the single biggest lever to pull.
Of the 28 who began a conversation, 25 returned for 3+. The leak is at the door, not inside the room.
This is the clearest result of the pilot. Of the children active in Week 1, 70% were still active in Week 3 (7 of 10), and 60% in Week 2 — with no reminders, no streaks, no nudges of any kind.
Education apps typically lose 85–90% of their starters by Week 3; even Duolingo, the category leader, sits around 28–40%.
Two things rule out the easy explanations:
A second signup cohort of roughly 15 children, joining in mid-April, produced the same early-retention shape (W1→W2).
8 children kept using Kiki on their own after the pilot formally closed on 21 April — 30+ further conversations the next week, at a longer average session length than during the trial itself. Voluntary engagement after novelty has stopped being the explanation.
Topics ranged from "my day" and "my family" to Diwali, Holi, Raksha Bandhan, festival foods, and talking to grandparents — half the returning cohort tried eight or more.
At the end of every conversation, Kiki flags the child's specific errors and walks them through the corrections. Across the pilot this produced 997 individual corrections — in aggregate, a real-time picture of where these children struggle, of a kind that is hard to get from classroom observation alone.
The near-absence of sentence-structure flags is the curriculum caveat made visible: these well-taught children already form complete, well-shaped Hindi sentences. What they need is polish — verb endings, गा/गी/गे agreement, and the Hindi word for the thing they only know in English. Gender agreement, the quietest and most consistent gap at 22%, is the classic heritage-speaker error pattern — exactly what daily at-home practice is built to chip away at.
Within three weeks, on the same topics, individual children were already producing cleaner Hindi: one child's average sentence length rose from 4.7 to 12.4 words per turn between Week 1 and Week 3; another's grammar errors per conversation fell by roughly 80%. These are early indicators in the children who returned, not a claim of measured fluency gain.
The same cohort included children who barely spoke Hindi, who fell back to English mid-sentence, or who had no one at home to practise with. For those children the design question is not "does Kiki grade them?" — it is "does Kiki keep them in the conversation and hand them the Hindi they are missing?" Three real exchanges from the pilot (names changed):
This is the behaviour that decides whether a heritage-learning product works for the whole class rather than only the children who were already doing fine — and it is exactly what a general assistant, built to correct or simply to answer, does not do.
None of this is rehearsed dialogue. It is what daily practice looks like when a child chooses it.
of Week-1 children returned in Week 3 — no reminders, no nudges.
of children who started came back for 3+ conversations.
kept using Kiki voluntarily after the trial formally closed.
Sentence length +164%, grammar errors −80% in three weeks, for the children who returned.
Fluency or measured accuracy growth. Heritage-language research (Polinsky 2018; Montrul 2016) consistently finds that grammatical-accuracy shifts in children who already speak a language conversationally require 3–6 months of sustained exposure, not three weeks.
That is not a weakness in the product; it is how language acquisition works for heritage learners. The practice habit — which is what was in doubt — is now demonstrated, and the accuracy gains follow from sustained use.