Although be-verbs—especially is, are, was, and were—remain central to our language, good writers moderate them. They’re sluggish. Action verbs, by contrast, make writing go: they kick, jolt, jump-start, halt, fly, flash, dampen, upset, soothe, hurt, and heal. You get strength from good verbs.
Want to improve a draft? Try this: on your computer, search for “is,” challenging yourself to eliminate it. Then do the same with “are.” You might be astonished at how effectively you streamline your paragraphs.