It's probably a generational issue. But keep in mind that virtually all résumés, cover letters and email communication will be read by the people who are hiring; and more likely than not they will be from a generation where good language skills and communication were valued. Yes - spelling and grammar does count on your resume!
Think about it. If someone hires you to do a job, shouldn't they expect that you are going to be able to communicate in the same standard that your 10th grade English teacher required?
Lucky you, you rarely have to worry about penmanship anymore. But be aware, relying solely on spell check is not going to necessarily help you.
Even with all of our modern technology, you'd be surprised to see what pops up on cover letters, résumés and/or follow up emails and texts. These glaring errors can often eliminate the candidate even if he or she seems to be the right person for the job.
Here are some surprisingly bad, yet real examples.
1) R u still hiring?
Even if the company is still hiring, it probably won't be you. Because a hiring manager is not expecting to get a letter or an email that is written like a text between two 16 year old BFFs. If you want to know if the company is hiring, ask like an adult would by spelling it out. As in, are you still hiring. Maybe you still won't get hired, but at least you won't be disregarded right off the bat.
Another high school piece of slang that is meant to ask "What's up?" According to Urban dictionary, the definition of Sup is A term that cool people use because they are too damn lazy to say What's up.
You're not that cool. Especially to someone who has the power to hire you. And really think this through for a moment. Are you really too cool (or too lazy) to actually spell out
what's up? But while we're on the subject, What's up is so inappropriate for even a casual email, that we're hoping you weren't even thinking of using it anyway.
3) Me and my boyfriend just moved here and I am looking for a job
Please, please, please if you start any of your sentences with Me and STOP IT RIGHT NOW. There is NO situation in the English language where it is appropriate or grammatically correct to say Me and. NONE. Without asking you to retake a grammar course, just get yourself out of the habit of saying Me and (and it is just a habit). A terribly bad habit which makes the speaker sound ignorant. The correct way to say it is, My boyfriend and I.
4) There, their, they're, your, you're
If this is a weak spot of yours, take a half an hour out of your life to learn the difference between the meanings of there, their, they're and your and you're. They all mean completely different things. But it's only five words. Surely you can spend 30 minutes on learning how to use them correctly.
The bottom line is this: If you can't take the time to learn how to write in a grammatically correct fashion, then what you are telling the hiring manager is that you lack attention to detail. Or worse yet, you didn't pay attention during your school years. Or possibly, the worst case scenario of all; you have a "who cares" attitude. And if you don't care, why should they?