Children gain certain abilities at certain ages. The acquisition of these abilities depend on the health of the neural-muscular system and the conditions of five senses in addition to a normal intelligence level.

1. Posture and Movement: The head falls back when a newly born is vertically positioned. In the third month, the head follows the body and stands straight. A 6 months old child sits with support whereas a 7 months old can sit without any support. A 5-6 months old baby can step whereas a 12-13 months old baby can walk without any support.

2. Hand and eye coordination: A 8 months old baby looks carefully at a toy 25-30 cm away and follows this with his/her head and eyes. After first two months, the baby starts to show interest towards the faces of people and his environment.

3. Hearing-sound-speaking: If the baby hears a sound, he may process it into a sound source in 3-4 months. An 8-9 months old baby understands a lot of words and says 1-2 meaningful words when he/she is 11-12 months old. He/she can form a sentence at 3 years old. It is possible to talk about an evident delay in speech, if an infant is not capable of saying meaningful words at the age of two, or if an infant fails to form short sentences at age 3, and if an infant fails to make understandable sentences the age of 4.

4. Social behavior: A 4-8 months old baby expresses happiness by smiling when he/she sees his/her mother. After 9 months, he/she starts to express dislike when he/she sees foreigners, starts to play by moving his/her hands when he/she is 3-4 months old and starts to play games imitating older people when he is 18 months old. The baby can chew solid nutrients at age of 9 monts and can eat by himself/herself using utensils at the age of 3. He/she can dress up by himself/herself when he/she is 4 years old, can inform parents in cases of urinary leakage when he/she is 15-18 months old. He can inform parents about his/her pee in the mornings when he/she is 2 years old and can inform them both during the day and night when he/she is 3 years old.