The milestones that matter
By 12 months: babbling with gestures, one or more words, responds to name. By 18 months: 20+ words, follows simple directions. By 24 months: 50+ words and two-word combinations ('more milk', 'aba jao'). By 3 years: three- to four-word sentences understandable to strangers.
These are floors, not ceilings. A child with zero words at 18 months or no two-word phrases at 24 months needs an evaluation — not a wait-and-see.
Late talker vs. language delay
A true 'late talker' (about 15% of toddlers) understands well, gestures, plays socially, and only words lag — many catch up by school age. A language delay shows broader patterns: poor comprehension, few gestures, limited play, or lost words. The second group does not reliably catch up without help.
You cannot distinguish these at home. An SLT can in one session — which is exactly what screening is for.
Bilingual homes are not the problem
A common Bangladeshi belief is that mixing Bangla and English 'confuses' children and delays speech. Research is clear: bilingualism does not cause delay; milestones apply to the combined vocabulary of both languages.