Your baby learns to talk during their first two years of life. But, long before they utter their first word, they are learning the rules of language and how to use it to communicate. 

Your baby learns to talk during their first two years of life. But, long before they utter their first word, they are learning the rules of language and how to use it to communicate. 
Researchers believe the work of understanding language begins while a baby is still in utero. Just as your unborn baby gets used to the steady beat of your heart, they tune into the sound of your voice and can discern yours among others.
When they begin to communicate they use their tongue, lips, palate, and any emerging teeth to make sounds (cries at first, then "ooh's" and "ahh's" in the first month or two, and babbling shortly thereafter). Soon those sounds will become real words – "mama" and "dada" may slip out and bring tears to your eyes as early as 6 months.
From then on, your baby will pick up more words from you and everyone else around them. Sometime between 18 months and 2 years, they should begin to form two- to four-word sentences. As your baby makes mental, emotional, and behavioural leaps, they are increasingly able to use words to describe what they see, hear, feel, think and want.
How do babies start talking?
Birth to 3 months
Crying is your baby's first form of communication. And one cry doesn't fit all- A piercing scream may mean she's hungry, while a whimpering cry may signal that she needs a nappy change. As she gets older, she'll develop all different types of gurgles, sighs, and coos.
3 to 6 months
At this stage, your child starts to babble, combining consonants and vowels (such as "baba" or "yaya"). At about 6 months she can respond to her name.
You may hear the first "mama" or "dada" now and then too. Though it's sure to melt your heart, your baby doesn't equate those words with you quite yet. That comes later when she's almost a year old.
At this stage, babbling sounds the same, whether you speak English, French, or Japanese in your home. You may notice your child favouring certain sounds (like "ka" or "da"), repeating them over and over because she likes the way they sound and how her mouth feels when she says them. (Ours is Hiya!)
6 to 12 months
When she babbles and vocalizes now, your baby sounds as if she's making sense. That's because she's trying out tones and patterns similar to the ones you use. Encourage her babbling by talking and reading to her.
12 to 18 months
Now your little one is using one or more words, and she knows what they mean. She'll even practice inflection, raising her tone when asking a question by saying "Up-py?" when she wants to be carried, for example. She's realizing the importance of language as she taps into the power of communicating her needs.
18 to 24 months
Though she probably says fewer than 50 words, your child now understands much more than she can say. And she picks up more words every day, so watch your language! She may even string two words together, making basic sentences such as "Carry me."
By the time she's 2, your child may use two- to four-word sentences and sing simple tunes. As her sense of self-matures, she'll start talking about what she likes and doesn't like, what she thinks and feels.
Pronouns may confuse her, which is why she might say "Baby throw" instead of "I throw."
24 to 36 months
Your toddler may struggle for a while to find the appropriate volume to use when talking, but she'll learn soon enough. She's also starting to use pronouns, such as "I," "me," and "you."
Between ages 2 and 3, your child's vocabulary continues to expand, and she understands most of what you say to her. She'll string nouns and verbs together to form simple sentences, such as "I go now."
By the time your child turns 3, she may be a pretty sophisticated talker. She'll be able to have a conversation and you'll be able to understand most of what she says. She'll even oblige when you ask her to do more than one thing at a time. ("Get the toy and put it back in the toy box.")
What if my baby is not talking?
If you are concerned about your child’s speech development, you should speak to your GP or PHN. The sooner a language delay or hearing problem is identified, the sooner treatment can begin. You should contact your GP and PHN if your baby isn’t attempting to make sounds, will not make eye contact with you, or doesn’t respond to her name by six months. Your baby doesn’t babble at nine months. Your child can’t follow simple instructions or speaks in only single words by her second birthday.
All children develop at different rates, but if you are worried, it is always worth seeking help. If your GP shares your concerns, you will be referred to a specialist.
Written by Laura Doyle staff writer at FFHQ who also blogs at www.lovelifeandlittleones.com.