Hope,
This is a great question! Heading into upper forms of education, copywork begins taking on a new focus. As students copy from increasingly more difficult narrative history books and classic literature, they are noting an author's style, voice, word choice, use of descriptive language, choice of vivid wording, use of humor, foreshadowing, creation of mood, important dialogue, etc. In essence, they are copying from great writers and beginning to internalize the author's use of language.
This is an excellent strategy, and one used by many of our founding fathers as a part of their education and all through their lives. Benjamin Franklin was known for copying lengthy passages from the Bible and from Pilgrim's Progress, which he then later tried to write verbatim without looking at the model. Thomas Jefferson was also know to copy extensively from various works in an effort to internalize the material and note important phrasing.
In high school, students continue keeping a Common Place Book, selecting quotes or passages that are meaningful to them from their classic literature for inclusion in their book. Charlotte Mason advocated this practice throughout high school, and we feel it is an excellent use of students' time as they watch for notable quotes or passages as they read, select from among them, and accurately copy them into their book for later reference.

Continuing copywork of Scripture is another area that is well worth time spent copying. Within HOD, students typically copy verses and passages that they have been asked to memorize, making the Scripture within their Common Place Boosk especially meaningful. Poetry is one more area that is worth copying, as the structure of the poems, the flow of the words, the sentiments evoked by the poetry, and the style of the poet are reflected.
Copywork is such an overlooked skill especially as students begin doing more of their own writing, however the inclusion of copywork in HOD makes sure that students are continuing to take note of excellent writing. It keeps students watching how strong writers express themselves and keeps students thinking of ways that they can imitate great writing. When students read and then copy from what they read, they remember better what was read. The quotes help the student recall the book to mind.

So, there are many benefits to copywork all throughout life, no matter what age you are!
Blessings,
Carrie