Now we've learned some of the basics of grammar, you have to apply them to your own writing. Sometimes, writing rules can and should be broken for the sake of an authentic voice.
The tone of your book is important, and every sentence guides the reader through the story. A YA contemporary won't be written like a scientific paper, so how do you know when to use your authentic voice?
Particularly in dialogue, your characters will speak a certain way that doesn't always follow writing rules. This might mean they talk fast, skipping commas, or their sentences sometimes jumble together incoherently.
This comes down to tone of voice. If you want your writing to be snappy, avoid excess commas. If you want it to be flowy and descriptive, don't be afraid of some exciting punctuation.
The most important thing to remember is that your writing must still make sense to the reader. You have to read your work aloud and decide yourself where punctuation should be placed.
Breaking the rules of spelling is more difficult, because the smallest deviation can change the entire meaning of a word. But that doesn't mean it can't be done at all.
Phonetic spelling (spelling words as they sound), for example, can be used to show someone's accent. Often, though, it's avoided, as it can be jarring to readers. An entire book written phonetically would be very difficult to read, but to add flair to a character who only appears once or twice, it can be entertaining.
Slang, similarly, says a lot about a character. Just make sure the slang can be understood by your readers. New slang can take a while to be added to the dictionary and become a 'real word', but you can still use it.
You might also break spelling rules by making up your own words. This is especially common in fantasy, in which writers are creating an entire society. Why wouldn't the people in this world have some of their own language?
Don't forget to come back next Monday to discuss Creating a Style Guide, and sign up to the All Write Newsletter to never miss a blog.