Typical Language Development

6 Months:
- Vocalization with intonation
- Responds to his name
- Responds to human voices without visual cues by turning his head and eyes
- Responds appropriately to friendly and angry tones

12 Months:
- Uses one or more words with meaning (this may be a fragment of a word)
- Understands simple instructions, especially if vocal or physical cues are given
- Practices inflection
- Is aware of the social value of speech

18 Months:
- Has vocabulary of approximately 5-20 words
- Vocabulary made up chiefly of nouns
- Some echolalia (repeating a word or phrase over and over)
- Much jargon with emotional content
- Is able to follow simple commands

24 Months:
- Can name a number of objects common to his surroundings
- Is able to use at least two prepositions, usually chosen from the following: in, on, under
- Combines words into a short sentence-largely noun-verb combinations (mean) length of sentences is given as 1.2 words
- Approximately 2/3 of what child says should be intelligible
- Vocabulary of approximately 150-300 words
- Rhythm and fluency often poor
- Volume and pitch of voice not yet well-controlled
- Can use two pronouns correctly: I, me, you, although me and I are often confused
- My and mine are beginning to emerge
- Responds to such commands as "show me your eyes (nose, mouth, hair)"

36 Months:
- Use pronouns I, you, me correctly
- Is using some plurals and past tenses
- Knows at least three prepositions, usually in, on, under
- Knows chief parts of body and should be able to indicate these if not name
- Handles three word sentences easily
- Has in the neighborhood of 900-1000 words
- About 90% of what child says should be intelligible
- Verbs begin to predominate
- Understands most simple questions dealing with his environment and activities
- Relates his experiences so that they can be followed with reason
- Able to reason out such questions as "what must you do when you are sleepy, hungry, cool, or thirsty?"
- Should be able to give his sex, name, age
- Should not be expected to answer all questions even though he understands what is expected

4 Years:
- Knows names of familiar animals
- Can use at least four prepositions or can demonstrate his understanding of their     meaning when given commands
- Names common objects in picture books or magazines
- Knows one or more colors
- Can repeat 4 digits when they are given slowly
- Can usually repeat words of four syllables
- Demonstrates understanding of over and under
- Has most vowels and diphthongs and the consonants p, b, m, w, n well established
- Often indulges in make-believe
- Extensive verbalization as he carries out activities
- Understands such concepts as longer, larger, when a contrast is presented
- Readily follows simple commands even thought the stimulus objects are not in sight
- Much repetition of words, phrases, syllables, and even sounds

5 Years:
- Can use many descriptive words spontaneously-both adjectives and adverbs
- Knows common opposites: big-little, hard-soft, heave-light, etc
- Has number concepts of 4 or more
- Can count to ten
- Speech should be completely intelligible, in spite of articulation problems
- Should have all vowels and the consonants, m,p,b,h,w,k,g,t,d,n,ng,y (yellow)
- Should be able to repeat sentences as long as nine words
- Should be able to define common objects in terms of use (hat, shoe, chair)
- Should be able to follow three commands given without interruptions
- Should know his age
- Should have simple time concepts: morning, afternoon, night, day, later, after, while
- Tomorrow, yesterday, today
- Should be using fairly long sentences and should use some compound and some    complex sentences
- Speech on the whole should be grammatically correct

6 Years:
- In addition to the above consonants these should be mastered: f, v, sh, zh, th,1
- He should have concepts of  7
- Speech should be completely intelligible and socially useful
- Should be able to tell one a rather connected story about a picture, seeing relationships
- Between objects and happenings

7 Years:
- Should have mastered the consonants s-z, r, voiceless th, ch, wh, and the soft g as in George
- Should handle opposite analogies easily: girl-boy, man-woman, flies-swims, blunt-sharp short-long, sweet-sour, etc
- Understands such terms as: alike, different, beginning, end, etc
- Should be able to tell time to quarter hour
- Should be able to do simple reading and to write or print many words

8 Years:
- Can relate rather involved accounts of events, many of which occurred at some time in  the past
- Complex and compound sentences should be used easily
- Should be few lapses in grammatical constrictions-tense, pronouns, plurals
- All speech sounds, including consonant blends should be established
- Should be reading with considerable ease and now writing simple compositions
- Social amenities should be present in his speech in appropriate situations
- Control of rate, pitch, and volume are generally well and appropriately established
- Can carry on conversation at rather adult level
- Follows fairly complex directions with little repetition
- Has well developed time and number concepts


http://www.childdevelopmentinfo.com/development/language_development.shtml