WHEN USUALLY CHILDREN BEGIN TO SPEAK?

In general, children say their first words between 12 and 18 months of age. They begin to use complex sentences by the age of 4 to 4 1/2 years. By the time they start kindergarden, children know most of the fundamentals of their language, so that they are able to converse easily with someone who speaks as the do. As with other aspects of development, language acquisition is not predictable. One child may use complex sentences at 5 1/2 years, another at 3 years.

Those videos speak about development of children´s speech.