Hello fellow marketers, English is only my second language, and though I myself think I'm pretty good at writing, I know there will be some odd words and sentences that even may be misunderstood by people who read it. So I'm anxious that articles and sales copy that I write won't do any good for my business. Internet business is very international so there must be a lot of people with similar problems. I'd like to hear what experience and opinions others have to this, and eventually how this issue might be solved.
I think you've just got to practice writing as much as you can - and also read a lot although I seem to remember a famous writer once saying that reading is the enemy of writing. You could always get someone (English?) to proof-read your work before you publish too... Good luck, Cheers, p.
Pondlife has a good point. You can always hire a proofreader to look over what you wrote. They will check for spelling, grammar, and punctuation errors. I do some proofreading in addition to my writing and my rate is $2 a page for general content and $3 a page for specialized topics like medical and legal (since they have specialized terminology). So, even if you have 20 pages of content, it may only cost you $40 or so to have it proofread. Note: A "page" is up to 500 words. I learned my lesson about pricing the hard way when I told someone I charged $2 per page and he sent me a "page" of website content with 23,000 words in it! I would also keep practicing your writing. You can join online writing groups and have your writing critiqued. This may help you better grasp some of the trickier points of the English language.
Sorry if this is being obvious but be sure to use the spelling and grammar checker of microsoft word or open office. They are not perfect but should help.