what are the stages of language and communication development from birth to 7 years?
['15 Months. Have about ten words that their carers can understand. ... ', "18 Months. Two words are put together e.g. 'bye bye dog'", '2 Years. Quickly learns new words. ... ', '3 Years. Speech is understood by strangers. ... ', '4 Years. Vocabulary is now extensive. ... ', '5 Years. ... ', '6 Years. ... ', '7 Years.']