While the words might trip lightly from your tongue in an ceaseless flow of fascinating verbiage, chances are that any speaker, consultant, or publisher is going to have to do some writing one day and, when they do, wouldn't it be nice to avoid some of the writing errors that brand us as amateurs? Here are a few particularly egregious errors.
1. Farther vs Further: Farther should be used when referring to a measure of distance, “His house is a little farther down the road.†If you're not referring to distance don't use farther. “His further comments caused the students to beat him about the head with broomsticks.â€
2. Your vs. You're: Only use “you're†as a contraction of the words “you are.†That's it. Your is a possessive form of a personal pronoun. To use “your†when you should use “you're†causes you're writing to stand out – in the wrong way.
3. There vs Their vs. They're: Those to whom correct grammar presents a challenge might prefer to have their fingernails forcibly removed by pliers than to contemplate the usage of these three words. Calm yourself and take a breath. It's not that hard. First off, “they' ;re†should only be used as a contraction for the words “they are.†Their is a possessive form of the word they. For example, “Their underwear was showing so he punched them in the face.†There refers to location or place, “There was no room for doubt that he was a terrible grammarian.â€
4. Its vs. It's: Only use “it's†when you are using a contraction for “it is†or “it has.†Leaving the apostrophe off indicates a possessive, such as “Its odor was offensive.â€
5. Affect vs. Effect: This pair is perhaps the most misunderstood pair of words in the English language.  Affect means to influence, as in “The rain affected Amy's hairdo.†Effect is normally associated with a result, “The effect was eye-popping.†Most of the time, say 95%, affect is a verb and effect is a noun. As far as the other five percent goes, good luck.
Obviously, the preceding list is a random sampling from among the hundreds of problems encountered when writing English language. Your mileage may vary.
The Speaking of Wealth Team
Flickr / B Rosen