This article presents a functional grammatical analysis of the writing
that 128 seventh and eighth grade students produced in response to th
eir science teacher's directive to describe a picture. It identifies t
he register elements of this task, demonstrating that relational verbs
, expanded noun phrases, verb tense, and clause themes are grammatical
features that are functional for describing. The paper also identifie
s the grammatical difficulties that this task posed for students who i
nclude English language learners and speakers of non-standard dialects
. Functional analysis can suggest the grammatical issues that are most
relevant for a particular kind of assignment, providing teachers with
information about the grammatical resources that enable students to c
onstruct more effectively the genres expected in academic contexts. Th
is study also shows that through their grammatical choices, students d
isplay different orientations to the assignment. Some demonstrate an u
nderstanding of expectations for analytical writing, while others refl
ect more personal orientations. Information about how grammar contribu
tes to the realization of particular school-based genres is seldom mad
e explicit to students. With an understanding of the register features
of academic writing tasks, teachers can help students use the grammat
ical resources available to them to expand and develop their writing s
kills.