Write routinely over extended time frames (time for research, reflection, and revision) and shorter time frames (a single sitting or a day or two) for a range of tasks, purposes, and audiences.
Common Core State Standards, Grades 9-10, Writing · Read it at the source · Checked October 14, 2026
What W.9-10.10 Means in Plain English
Ninth and tenth graders write at two speeds: research papers drafted, reflected on and revised over weeks, and pieces finished in one sitting, like a fifteen-minute biology explanation of why onion cells shrink in salty water. The tasks, purposes and audiences change from week to week.
Eighth grade (W.8.10) names discipline-specific tasks; grades 9 to 10 leave that phrase to WHST.9-10.10 and keep both time frames for a range of tasks, purposes and audiences. Grades 11 to 12 (W.11-12.10) use the same wording as grades 9 to 10.
W.9-10.10 I Can Statements
I can write a clear, complete response in a single sitting.
I can research, reflect on and revise a long piece over weeks.
I can adjust my writing to each new task, purpose and audience.
W.9-10.10 Worked Example
A fifteen-minute quick write after a biology lab, the short end of W.9-10.10. Both students saw the same cells; only one explained them.
Prompt
Biology quick write, 15 minutes. In today’s lab, red onion skin cells looked full under the microscope. After a few drops of 10 percent salt solution, the colored part of each cell shrank and pulled away from the cell wall. Explain what happened and why, for a classmate who missed the lab.
Not YetThe cells shrank because of the salt. The salt sucked the water out of them. This is called osmosis.The term is right, but the explanation is a slogan: salt does not suck, nothing says where the water went or why, and a classmate who missed the lab would not know which part shrank or why the wall stayed put.
Meets the StandardThe onion cells lost water by osmosis, the movement of water across a membrane from where water is more concentrated to where it is less concentrated. In plain water the cells stayed full, because water was at least as concentrated outside the cells as inside. The salt solution made the water outside the cells less concentrated than the water inside, so water moved out through each cell membrane. As the cells lost water, the membrane and the colored vacuole inside it shrank, which is the part we saw pull away. The cell wall stayed in place because it is rigid, so the gap between wall and membrane grew. If we had rinsed the cells with plain water afterward, water would have moved back in and the cells would have filled again.In fifteen minutes the writer defines the term in a sentence, explains the cause in the order it happened, ties each step to what the class saw under the microscope and ends with a prediction that tests the explanation. That is the short end of W.9-10.10; the long end is a lab report or research paper revised over weeks.
Moves to Use
Name the process and define it in the first sentence.Explain the cause step by step, in the order it happened.Tie each step to something the reader could see.End with a prediction or check that uses the explanation.
Common Mistakes with W.9-10.10
Writing only at the end of a unit
One research paper in May and no writing in the weeks before it
Try this: Schedule short writing at least twice a week, and break the long paper into dated drafts, reflections and revisions.
Quick writes that are just vocabulary
“This is called osmosis.” as the whole explanation
Try this: Require each quick write to explain why or how in three connected sentences, with the vocabulary word used, not just named.
One audience all year
Every piece written for the teacher, in the same five-paragraph shape
Try this: Rotate the named reader, such as a classmate who missed the lab, a younger student or a local official, across the year.
Writing Prompt GeneratorFree ToolGenerate short prompts for one-sitting writing across subjects, then keep the best ones for a twice-weekly quick-write routine.Quick writeGrades 9-10Informative
Why did the colored part of the onion cells shrink?
The salt solution made water less concentrated outside the cells than inside, so water left through each cell membrane by osmosis, and the membrane and vacuole shrank.
Why did the cell wall stay in place?
The cell wall is rigid, so it kept its shape while the membrane pulled away from it, which widened the gap the class saw.
What two time frames does W.9-10.10 ask for?
Extended time frames, with time for research, reflection and revision, and shorter ones: a single sitting or a day or two.