Parents wait for the first word as the real milestone. In fact, things happen before words that predict more than a word count does - and those things can be observed earlier.
The non-verbal foundations
Language is not built on sounds but on the child's desire and ability to connect with another person. These abilities come first, and when they are missing, words rarely arrive on their own.
- Eye contact: the child seeks your face and holds their gaze.
- Response to their name: they turn when called.
- Joint attention: they look at what you are looking at, and check with their eyes whether you are looking too.
- Pointing: they point to request, and later point simply to show you something.
- Imitation: they copy sounds, gestures, movements.
- Turn-taking: they wait their turn in simple games, such as handing an object back and forth.
Pointing deserves a note of its own. A child who points only to obtain what they want is at a different level from a child who points to share attention - 'look at that'. The second is a good sign of the social development of communication.
Signs that call for assessment
- The child does not respond to voice or to their own name.
- Eye contact is rare or avoided.
- They do not imitate sounds or gestures at all.
- They do not point and do not seek your attention.
- They do not babble or produce consonant sounds.
- They have lost a skill they previously had.
The last point - regression - should be assessed without waiting, at any age. Losing a skill is a different sign from never having reached it.
Hearing is a precondition
Language is learned through hearing. Where there is any doubt about a child's response to voice, a hearing check is standard professional practice and should come before other explanations are sought.
If you notice several of these signs, that does not establish a diagnosis. It establishes that an assessment is worthwhile - and the earlier it happens, the more time the work has to take effect.