I just learned that someone I know, a young man, just got a new job. He was overseas when he applied for it and could not interview in person, so the interview was done via Skype. Because of the nature of the job, most other candidates did the same. After he got the job he was told that one of the reasons he got it was because he wore a tie during the Skype interview.
The point, of course, is that good impressions are important. This young man was well-qualified and had other pluses going for him, but that’s not always enough. This confirms my own view that you are doing yourself a disservice if you don’t strive to make a good impression every way you can, whether it’s a job interview or that first Match.com meeting. That includes your language. The young man I mentioned also speaks well. He’s polite and uses good grammar.
One other thing worth noting: the interviewer did not tell the losing candidates that they lost because they were wearing tee shirts or sweatshirts. In other words, if you aren’t making a good impression for any reason – your posture, your clothes, your tattoos, your language – people aren’t likely to tell you (except maybe your mother), but you will continue to lose out. It’s up to you to recognize your own shortcomings (or at least listen to your mother) and straighten out.