What is common in all cultures about children learning to speak?

What is common in all cultures about children learning to speak is the fact that their first sounds are similar in all cultures.

Linguists have studied all 5000 languages of the world, and they noticed that all languages use the vowel sound aah, ee, and ooh which are the same vowel sounds a baby produces first.

So we can say that, although each baby learn at his own speed, all of them produce the same first words in all cultures.

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