Lang. Acquisition – SYNTATIC and MORPHOLOGICAL Components.
MEAN LENGTH OF UTTERANCE ▪ Definition: The average # of morphemes per utterance. ▪ To Calculate MLU: Identify the # of morphemes per utterance and determine the total # of morphemes in the sample. Divide the total # of morphemes by the total utterances.

-The use of MLU is a good indicator of language development for earlier stages (2 to 4 yrs.), but doesn’t always indicate the true complexity of use.

* Brown’s 14 morphemes chart and OWENS 1991. It lists morphemes and age of mastery, on the following page is the Retherford version that tracks linguistic development. Good to study this for overall picture of grammar acquisition.*

Brown’s Five Stages (listed in the Rutherford Text, Owens (1991) text). Below is based on Owens book.

Early Stage I: MLU =1.-1.5 Age=12-22 mos.
|Negative |Interrogative |Embedding |Conjoining |Intrasentential |
|Single word: no, gone |Yes/no asked w/rising | |Serial naming w/o and |Pronouns I and Mine. Only|
|Neg.+ X = no eat. |intonation on single word| |(coat, hat) |isolated nouns |
| |=what /where | | |elaborated. |

Late Stage I: MLU = 1.5-2.0 Age= 22-26 mos.
|Negative |Interrogative |Embedding |Conjoining |Intrasentential |
|No and not |That + x. What +noun | | | |
| |phrase + doing? | | | |

Early Stage II: MLU=2.0-2.25. Age=27-28 mos.
|Negative |Interrogative |Embedding |Conjoining |Intrasentential |
| |Where + noun phrase |Prepositions in and on |And (coat and hat) |Pronouns: me, my, and |
| |going? | | |it, this and that. Ing |
| | | | |and plural markers. Noun |
| | | | |elaboration in object |
| | | | |postion. |

Late Stage II: MLU=2.25-2.75 Age=29-30 mos.
|Negative |Interrogative |Embedding |Conjoining |Intrasentential |
|No, not, don’t and can’t.|What or where + subject +|Gonna, wanna, gotta, etc.| | |
|Neg. element placed |predicate. |(she mentioned these are | | |
|btwn.subject and pedicate| |KEY in showing up. | | |
| | |Infinitive phrase appear | | |
| | |in object position. | | |

Early Stage III: MLU=2.5-2.75 Age=31-32 mos.
|Negative |Interrogative |Embedding |Conjoining |Intrasentential |
| | | |But, so, or and if |Pronouns she, he, her, we|
| | | |appear.Begin clauses with|, you, your, yours and