Brief speech development scale (Comparison of English and Japanese):
Speech development scale differs in what language the child uses as a mother tongue. (Reminder: There is no /F/,/V/,/R/,/TH/ sounds in Japanese.)
| English | Japanese | ||||
| Approximate age | sounds | language skills | Approximate age | sounds | language skills |
| 6 months~ | A,O,E | babble | 6 months~ | A,O,E | babble |
| 1 years~ | I,U,P,B,M,N | holophrastic stage, two-word stage | 1 years~ | I,U,P,B,M,N | one-word stage |
| 2 years~ | T,D,H,F | telegraphic stage | 2 years~ | T,D,H | two-word stage |
| 3 years~ | K,G,V | multi-word stage, phonological awareness | 3 years~ | K,G | three-word stage |
| 4 years~ | L,S,Z,CH | use of a sentence with more than four words | 4 years~ | L,CH | phonological awareness, use of a sentence with more than four words |
| 5 years~ | R,TH | reading simple letters | 5 years~ | S,Z | controlling particles, reading simple letters |