You really don't have to 'correct' your child to teach them the correct way to speak. MODELLING and REPETITION are incredibly powerful, and you can make a big impact by doing 

WHY?
Nobody wants to be corrected. Saying "say______", "that's not how you say it" or "copy me" can quickly knock your child's confidence with talking and can also cause lots of frustration. It's totally unnecessary and some children feel embarrassed.

On the other hand - not saying ANYTHING doesn't cause harm but it's not teaching the next step. Similarly, if you just repeat what your child says, they're going to think their sentence was correct and will take longer to learn the correct structure.

INSTEAD:
Say the phrase back to them positively with the correct structure. Make your voice sound like you're agreeing with them and say it a few times. Repetition is magic.

OUR EXAMPLE.
Listen closely. August says "Babbitty bunny don't have a mouth". I respond by saying "Babbitty bunny DOESN'T have a mouth" and make my voice sound like I'm totally agreeing. I say "doesn't' a few times and repeat the full phrase AGAIN. At the end, August says "doesn't have a mouth". He imitated the correct structure in less than a minute and I didn't even have to ask him to. MAGIC.

IT FEELS WEIRD.
I hear you. I'm a speech therapist - this comes naturally to me. You're probably going to feel really weird doing lots of repetition and sounding super positive. Your child might think you sound weird too. But actually, that's PERFECT. The more odd you sound, the more likely your child will tune in, listen and they and copy.

How confident do you feel to try this strategy with your little one? 1=not confident, 10=super confident.

Watch the video example here