What are the reasons for loneliness even after surfing the online dating sites? Popular online dating site 'Zoosk' reveals that 'the one thing' that is responsible for dating melancholy is 'poor grammar' reports News.com.au. The study surveyed more than 9000 Zoosk singles looking at the extent to which poor grammar affected an individual's attraction levels across different age groups. The survey found that nearly half of singles almost 48 per cent considered grammar to be a deal-breaker in online dating. Blatant spelling errors are a turn-off to the majority of singles. (Read: 5 ways to crack online dating) According to