The purpose of this study was to explore the linguistic architecture of instructional language used during first grade read aloud lessons. The participants were from the CTL Year-3 Read Aloud study. The study's random assignment created 20 teachers in the treatment group and 19 teachers in the control group. My study investigated the variability of their teacher's use of instructional language during direct instruction read aloud lessons. Specifically, I analyzed the following linguistic attributes: (a) clausal density, (b) number of different words, (c) words per minute, (d) percentage of maze words, and (e) number of abandoned utterances. Exploratory associations for these variables were compared against the Quality Classroom Instruction protocol (QCI), a measure of teaching effectiveness. The results of my study yielded null effects due study limitations. However, the explored area addressed a blind-spot within the literature and provided preliminary data, insight, and recommendations pertaining to the linguistic attributes of instructional language used by first grade teachers during read aloud lessons. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]