Part 2 of the Wikihow listicle "Be a Good Writer" is about learning vital skills, and item 3 of part 2 says you should "Learn the rules of grammar". Where should you turn to find out what they are? The article (as accessed on March 2, 2015) says:
If you have a question about grammar, refer to a grammar book, such as The Elements of Style by William Strunk and E. B. White or The American Heritage Book of English Usage.
And the link attached to the title The Elements of Style is to an online reproduction of the text of the original 1918 edition of Strunk's dreadful little book of drivel.
O God, grant me thy precious gift of patience… and I need it right now.
Virtually nothing useful about English grammar can be learned from Strunk. Setting aside a few standard conventions of punctuation, which barely deserve to be called part of the grammar, the grammatical claims Strunk makes are foolish assertions like that however in the sense "nevertheless" cannot be correctly used to begin a sentence; or that none of us cannot take plural agreement; or that passive clauses are inherently bad; or that they cannot have a singular antecedent (so No parent would harm their own child is a mistake; Strunk insists it should be No parent would harm his own child). Strunk condemns words as familiar as very or clever or system, and phrases as ordinary as six people or so warm or the student body. His booklet is replete with superannuated hogwash about English.
You can see that Strunk is telling untruths if you simply take a look at the usage in high-quality literary works published when he was in his prime. His claims not only aren't true of English now; they never were true, at any time in the history of the human species.
Some people think that I overstate the extent to which Strunk's booklet (and the even worse subsequent editions that were augmented and tampered with by E.B. White) harms the English teaching and writing instruction professions. I don't overstate it (though I will continue to try). I have set out clear arguments and evidence in an article in The Chronicle of Higher Education and in a longer paper in English Today, attempting to counteract the hundreds of thousands of web pages and writing instructors that praise Strunk and White every single day. The Wikihow listicle is only one particularly feeble example that happened to come to my attention.
Stay away from the advice of anyone who recommends Strunk (or Strunk and White). If you want a book on how to write, read Steven Pinker's superb book The Sense of Style. Compare, for example, Pinker's highly intelligent advice on using passive clauses in discourse (pages 132 to 135) with Strunk's dishonest and incompetent remarks about the passive. The two books are not only from different centuries, they're from different planets.