When do you use formal vs informal Indonesian?

Short answer

Indonesian has three register tiers: formal (Bahasa baku — used in writing, news, government, business), standard polite (default for strangers and work), and informal (Bahasa gaul — with friends, family, social media). Switch based on who you talk to (age, status, intimacy) and where (office vs café). The cardinal rule: when in doubt, go formal — Indonesians forgive over-politeness but resent under-politeness.

Why this matters

IndoLingua publishes structured Q&A pages for the questions Indonesian learners and travellers ask most often. Each page is reviewed by native Indonesian teachers and updated annually.

About IndoLingua

IndoLingua is a CEFR-aligned Indonesian (Bahasa Indonesia) learning platform with 180 lessons from A1 to C2, an AI conversation teacher, 4000+ flashcards, and a 9-language interface. Free discovery plan, no credit card required.