Do native speakers learn consonant and vowel length easily, or is it difficult?


Just want to ask if this is normal or I am just fighting the wrong way.

`かっこいい` say this word has the final 2 `い` which shall take 2 length of the `i`
sound.

I am struggling to keep trying to speak with 2 length letter period. I think
this is crucial to the meaning also to grow some sense of awareness about
this.

Will this be ever a problem for local Japanese to learn to speak? I mean if
with this type of word with 2 consecutive length of same sound, when you teach
how to say word without knowing the spell, is it even detectable by the child
or student? Is it some issue as well so you need to remind them that this
needs to pay attention?

I am not sure if I need to use my head for this because it becomes such
distraction as well. So it needs to become a habit for sure or sub-conscience
coordination of my brain and my mouth.

Anyways, just wondering how local Japanese teach this kind of word to
children.




I assume that you are asking whether native speakers can detect, as a child,
whether a vowel is long (マーナ) or short (マナ). The answer is yes, infants can
detect it by age 9.5 months according to the paper by [Sato, Sogabe, Mazuka,
"Discrimination of phonemic vowel length by Japanese infants" American
Psychological Association,
2009](https://psycnet.apa.org/record/2009-24671-002)




I assume that you are asking whether native speakers can detect, as a child,
whether a vowel is long (マーナ) or short (マナ). The answer is yes, infants can
detect it by age 9.5 months according to the paper by [Sato, Sogabe, Mazuka,
"Discrimination of phonemic vowel length by Japanese infants" American
Psychological Association,
2009](https://psycnet.apa.org/record/2009-24671-002)

