- Not using punctuation
- Not capitalizing the first word in your sentence.
These are all stylistic choices. The point of language isn’t to be strictly held to the rules, it is to get a point across. Concerning yourself with the rules only burdens yourself. It is better to communicate something in a successful way than to nitpick other people’s grammatical choices. If I get what a person is trying to say, that’s all that matters.
1: Your English teacher would strongly disagree.
2: This thread is not to be taken seriously.