From Quora: "Can I study [the] SAT grammar book instead of [the] ACT book for taking [the] ACT?"

Here's the link to the original Quora post:
www.quora.com/Can-I-study-SAT-grammar-book-instead-of-ACT-book-for-taking-ACT/answer/John-Linneball

Yes, you absolutely can. The “new SAT” from 2016 to the present is essentially the old (and present) ACT when it comes to the English/writing test. Any SAT review book meant for the “new SAT,” meaning from 2016 on, would work perfectly well. I like to use the Barron’s SAT books - again, any edition of that book from meant for the SAT for 2016 on would be fine (e.g. the 28th , 29th, or 30th editions).

You can also use my ACT and SAT videos for practice - here’s my playlist for English grammar for the SAT, ACT, etc. They’re free and they’re pretty great (okay, I produced them, so I may be biased).
I’d suggest you also practice on real ACT and SAT practice tests, which you can obtain from the College Board (SAT) :
Downloadable Full-Length SAT Practice Tests
Downloadable Full-Length Practice Tests Download eight official SAT practice tests for free.

https://satsuite.collegeboard.org/sat/practice-preparation/practice-tests and the following official ACTs (old ACT exams that are suitable for practice).
Here’s a page that links to several old, but real, ACTs you can use for practice. Don’t worry; the ACT English test doesn’t change much (basically, it doesn’t change at all) from year to year.

6 Free Official ACT Practice Tests | PrepMaven
We've got the 6 officially released ACT practice tests and proctoring instructions you need to supplement your ACT prep--and all for free!


​Hope this helps!
- John