Check yourself: Bad grammar is unprofessional

As a marketing director, I send a lot of work out to be written by in-house and freelance writers. Many of them are very good at their jobs and I have no complaints, but some of them are, duh, unprofessional. By that I mean that they are unable to write a simple article without making some pretty obvious grammatical errors. Maybe it is the era of texting that has made some of us sloppy, but that doesn't matter to me. My sales copy must be written correctly and professionally or I am sunk. Here are some of the common errors that I am talking about: Lose for loose: These two words do not mean the same thing. I can not stress that enough. Affect or effect: If you do not know the difference between these two, please stop writing and get a factory job. But, here’s a good trick to figure out if you are using the right one: For affect, try substituting the word “influence.” For effect, try substituting the word “result.” Semi-colons: Semi-colons are not commas, and they are not colons. Please dangle a participle before you abuse the right to add a semi-colon in a sentence. Use a semi-colon between two closely related independent clauses that are not conjoined by a coordinating conjunction, not just because you do not know what else to put there. It's for its. It's is the short form of it is. Its is the possessive form of it. Please stop throwing them together like they are interchangeable. Their, there, and they're. The difference is obvious. Please proofread your work before sending it to me. Then and than. Enough said. Than is a conjunction you use with comparisons, while then is an adverb that refers to time. If you are having trouble with any of these errors, please proofread your work slowly before wasting the time of some editor or a struggling businessman like myself. My time is stretched already. Reading sloppy work overloads my schedule.