Why the closeness is real but not a substitute for checking
Bahasa Indonesia and Bahasa Malaysia both grew from the same Malay root language, so a large share of everyday vocabulary, sentence structure and basic grammar lines up closely enough that many Indonesian speakers can follow Malaysian conversation with little adjustment. For household communication, that's a practical advantage over a candidate starting from an unrelated language.
The gap shows up in specifics rather than the whole language: some everyday words differ, a handful mean something different or opposite in each version, and spoken pace, accent and local slang take longer to adjust to than written or formal language does. A candidate's comfort level with this gap varies by her own exposure, not by nationality alone, so treat it as something to check, not something to assume.
- Shared vocabulary and grammar give many candidates a real head start.
- A handful of everyday words carry different meanings in each language.
- Spoken pace, accent and slang usually take longer to adjust to than basic vocabulary.
Questions that confirm two-way communication
Ask her to describe, unprompted, how she'd handle an ordinary task you'll actually give her, such as a child's morning routine or a specific cleaning sequence, using Bahasa Malaysia or whichever language you'll both actually use day to day. Listen for whether she can explain the steps in her own words, not just repeat words you've used first.
Then check the other direction: give her a short instruction she hasn't heard before and ask her to repeat back what she understood, in her own words. A candidate who paraphrases accurately understands you; one who repeats your exact phrasing back without variation may be following along less than it appears.
What to do if communication needs more time
A candidate who's clearly still building comfort in Bahasa Malaysia isn't automatically a weaker hire, some households manage well with a short adjustment period and simple, consistent instructions early on. What matters is knowing this going in, rather than discovering it in week one, so you can plan how you'll bridge instructions during that period.
If clear communication on safety-related tasks, such as a child's routine or medication reminders, matters most to your household, weight this interview question accordingly and consider a short trial period focused specifically on those tasks rather than general conversation.