To learn anything there are some specific levels. Similarly, children also learn speaking and listening step-by-step. Here, I would try to explain it in detail with the help of dividing it in age-groups.

Babies(0-12 months):

Here in this age, babies are just able to 

  • Respond to familiar sounds
  • Smile and make eye contact
  • Babble("ba-ba" , "da-da")
  • use gestures like waving.

Toddlers(1-3 years)

Here they are able to

  • Say simple words

  • Say short sentences(" Love you Mumma").

  • Point to objects

  • able to follow simple directions.

Preschoolers(3-5 years)

Now, they are somehow mature and can express themself by using:

  • Longer sentences.
  • Ask question . Specially "Why?" .
  • Tell simple stories.
  • play pretended games with language .for example teacher-teacher.

Early School Age(5= years)

Now, they are pretty mature, able to do study and:

  • Speak clearly

  • Use complex ideas.

  • Understand a wide vocabulary

  • carry full conversation.

Summary

Everything is gonna be easy if we divide it in parts. Similarly, here step-by-step learning is clear for children without any confusion because they learn according to their capacity and without any burden.

References:

Fellowes, J., & Oakley, G.
(2019). Language, literacy and early childhood education (3rd ed.). Oxford University Press.
Owens, R. E. (2020).
Language development: An introduction (10th ed.).
Pearson.