Stages in Child Development

Cooing Stage: This is the first stage of a child's language development. This stage can develop as early as siz weeks and the infants will start making spontaneous cooing noises such as "aaa, ooo, ahh". At its earliest stage, the child is trying to manipulate their tongues, mouths and breathing by making a series of sounds. This is often the case when the child is alone as they're experimenting with different noises.
At 8-20 weeks the child's phonology allows the child to improve their voice control meaning that the child is now producing softer sounds in order for them to test their new communication skills. The 'comfort' sounds consist of a constant vowel or consonant sound such as "coo, gaa" and "goo"

Babbling Stage: This is the second stage of a child's language development. Starting at infant stage, the child begins to try articulate sounds and uttering without any recognized words. This will go on to around 12 months when they will then be able to produce recognizable words though babbling may continue.
The types of babbling are reduplicated babbling "da da da da" and Non reduplicated babbling "ka da bu ba mi doy doy doy"
After 9 months the child will start to use gestures and body language to show that they're understanding the language but cannot express it.

Verbal Scribbling: This is the third stage of a child's language development. Starting around 20-30 week period the babies will begin to test their voices by changing pitch, volume, rate and quality. Over time the child will be able to use consonant and vowel sounds, be able to adjust pitch through playing an experimenting with their voices.
They will also begin to play with sounds from the nasal such as "mmm" and "nnn" and fricative such as "fff" are produced. They practice variety of sounds such as glides low-high and high-low and towards the end of the stage the child will be able to put together the vowel and consonant sounds which is the start of babbling.

Melodic Utterance Stage: This is the fourth stage of a child's language development. Starting from 9-18 months a child will begin to use intonation (tone), melody (pitch) and rhythm (pattern) of their voices. While developing some of their uttering may be misheard as a question due to them not learning how their tone of voice works and over time and depending on nationality of the child, will start to follow different rhythmical patterns such as "tum-ti-tum" for English children and "rat-rat-rat" for French children.

Lexical and Grammatical Development
Stage One: Holophrastic
These are single words used to convey many meanings. Starting at around the 12-18 month period, the child will utter their first word and build a vocabulary on this at holophrases which can reach about 50 words. (10x more words learned). They convey a meaning of a sentence/phrase through the body language, intonation and volume but the words will relate to the child's everyday life.

Stage Two: Two Words
These are two words formed together to make/use a sentence. Starting at 18 months The child is now able to choose the word order for their sentences which makes a simple grammatical analyses of the meaning of these 'sentences'. These are much more flexible with grammatical functions which are (1 action affects an object (2 actor performs an action (3 object given a location. However, the sentences may not make sense still for example "mummy-daddy" still has no grammatical correctness. But, the child will now have correct syntax (my bed), begin to use prepositions (on head), use possession words (my cat) and use pronouns (she cold).

Stage Three: Telegraphic
This is when the child begins to use sentence of up to four words in length. Starting at 2-2.5 years, a child will learn how to form proper sentences but still with some sentences being filled with gaps. This is where non-lexical words like 'and,'but', 'if', conjunctions such as 'the', 'a', articles such as 'is' and auxillary verbs are sometime missing and endings such as 'ing' are also missing. At this stage the child will use three conventions to get across what they want and these are statements, questions and commands.

Stage Four: Post Telegraphic Stage
This when a child has language to a point where they're able to give enough information in a sentence. Starting from around age 3 a child will begin to use this and increase their vocabulary from 50 words to around 13,000 words. The sentences are very basic for example “mummy eat carrot". At the end of stage, a child is likely to use plurals and joining words in order to try to grasp language and their tense.