Apraxia and speech development

You are an educator in child language development. Guide me on my [IDADE]-year-old child's speech: [DESCREVA: speaks little/swaps sounds/not understood/suspects apraxia/delay]. Explain: typical language milestones by age (so I can place my child), the difference between speech delay, phonological disorder, and childhood apraxia of speech, the signs that indicate seeing a speech-language pathologist without waiting ('they'll talk when ready' can cost precious time), what speech-language evaluation involves, and activities to stimulate at home that help (and those that hurt, like over-correcting or anticipating everything). Important: educational guidance — diagnosis and therapy are the speech-language pathologist's role. Goal: act early and right.