Pinyin spelling rules
You might think that pinyin has no "rules" other than simply memorizing correctly and then writing out the syllables in the pinyin chart. You'd be wrong! There are quite a number of issues that even native speakers get wrong. Getting them correct makes pinyin easier to read and less likely to cause confusion.
Why Learn the Rules?
Many of the rules of pinyin make pinyin easier to read and harder to misread. Most of these rules are of this type, and we encourage all learners to learn them.
It also helps you judge how well a school or teacher really knows their pinyin. (If they do, they should follow these rules, or at least be aware of them!)
The Key Rules
We won't get into all of the rules of pinyin, but we will cover a few that really help learners.
Separate Words with Spaces in Pinyin
You've probably seen books for Chinese kids where every character has pinyin, and there's spaces between the pinyin for every single character, as if there were no two-character words at all. This is totally wrong! Correct pinyin puts spaces between words. This makes it much easier to read and make sense of.
Capitalize Proper Nouns in Pinyin
The names of people, places, companies, brands, etc. should be capitalized in pinyin. When the name has multiple words in it, each word should be capitalized.
For Chinese people's names, The surname is capitalized and the given name is capitalized, but two-syllables given names should be written as one word (no space), with no intercaps, and not hyphenated.
Use English Punctuation with Pinyin
Chinese punctuation should not be used with pinyin. This is true for periods, commas, parentheses, colons, apostrophes, quotation marks, etc.
Make Syllable Boundaries Clear with an Apostrophe
This is one of the most important for making your pinyin legible. When the boundary between the end of a pinyin syllable and the beginning of another one is ambiguous, use an apostrophe between the two.
For example, if you see "pingan," that should be "pin+gan" and not "ping+an," which is correctly written as "ping'an."
In some cases, when you're using pinyin input to type Chinese characters, the input can't figure out what you're trying to type unless you correctly use the apostrophe in your pinyin.
Sources and further reading