The interwebs have been abuzz this week with gleeful snarking about Sanches v. Carollton-Farmers Branch I.S.D., particularly the Fifth Circuit's dressing down of Sanches' attorney for "grammatical errors ... so egregious and obvious that an average fourth grader would have avoided most of them." Ouch.    
Of course, checking your brief for spelling and grammatical errors is important, and not just so you can avoid having a federal court of appeals tell that you are approximately as literate as a 9-year-old. Much like having a run in your stockings (I hear nylons are making a comeback) or a stain on your tie, careless errors in your brief distract from the quality of your argument. Why slave for hours to craft a brilliant argument if the court is going to be too busy snickering over your failure to master subject-verb agreement to notice?
As if that's not enough, careless briefing can cost you money (I knew that would get your attention).
Consider the hapless advocate in Devore v. City of Philadelphia, who consistently submitted filings replete with typographical errors--including, most memorably, a typographical error in the word "typo." The result, when it came time to award attorney's fees, was a $150 reduction in the hourly rate claimed for written work. Again, ouch.Like the judge who made the attorney's fee award, I would be remiss if I did not reveal to you the full glory of counsel's carelessness:
As previously mentioned, [counsel's] filings are replete with typographical errors and we would be remiss if we did not point out some of our favorites. Throughout the litigation, Mr. Puricelli identified the court as “THE UNITED STATES DISTRICT COURT FOR THE EASTER [sic] DISTRICT OF PENNSYLVANIA.” Considering the religious persuasion of the presiding officer, the “Passover” District would have been more appropriate. However, we took no personal offense at the reference. In response to the attorneys' fees petition, the Defendants note that the typographical errors in [counsel's] written work are epidemic. In response to this attack, [counsel] writes the following:
As for there being typos, yes there have been typos, but these errors have not detracted from the arguments or results, and the rule in this case was a victory for Mr. Devore. Further, had the Defendants not tired [sic] to paper Plaintiff's counsel to death, some type [sic] would not have occurred. Furthermore, there have been omissions by the Defendants, thus they should not case [sic] stones.
If these mistakes were purposeful, they would be brilliant. However, based on the history of the case and [counsel's] filings, we know otherwise. Finally, in the most recent letter to the court, asking that we vacate the settlement agreement, [counsel] identifies the undersigned as “Honorable Jacon [sic] Hart .” I appreciate the elevation to what sounds like a character in the Lord of the Rings, but alas, I am but a judge.
The third time's the charm: ouch.

See: