Writing conventions are the glue that hold our written language together. They are the bits and pieces of language usage that seem so trivial when taught in English class.
However without these conventions meaning would be practically impossible to pull from the context of written message.
Children first encounter basic writing conventions within the context of books that are read to them. They notice the interestingly shaped exclamation and question marks. Quotation marks become important as understanding conversation becomes important. Rarely is the visually boring period mentioned unless there are three of them in a row and then...well that's a different matter. Periods really don't become "necessary" to the writer until he/she can fit more than one sentence on a page. That is usually towards the end of first grade or the beginning of second.
Use shared reading time of an old favorite book as a discussion setting for writing conventions. Choose only one point to discuss. Look for examples in other books.
When the need for punctuation arises in his/her writing, choose one item on which to focus. If you try to correct all of the punctuation, sentence structure, and tense problems at one sitting the young writer gives up on understanding what is happening and just passively follows your directions. This rarely leads to improvement in the next written piece.
Punctuation of any kind other than exclamation and question marks is probably not going to "take hold" until the child is well into the transitional stage of spelling. Remember that at the phonetic stage, the child is spelling what he/she hears. The question marks and exclamation marks are the only punctuation that make any difference in the way we speak.
Transitional stage spellers are relying more on their visual channel and readers "know" that periods are needed in text. When they first become aware of this need they try interesting strategies such as periods after every word or at the end of every line. This is just overusing a new talent. (Kind of like whistling 24 hours straight after you just learn how.) This practice quickly refines itself into more conventional punctuation with a little discussion and support.
Watch for opportunities to introduce these conventions first:
Capitals for "I" or proper nouns
Lower case letters used appropriately
Exclamation points
Question Marks
Periods
Quotation marks
Such conventions as paragraphing and sentence structure are best left for older students who can peruse their work at a glance. Younger students simply do not have the visual maturity to do this. It is important when "publishing" that the writing be in a correct form. When an editor sends in work to be published it has correct spelling and punctuation, although this is not always done by the writer.
Publishing provides extra incentive to continue writing. Everyone loves to hold an audience. The young writer can read and present his/her work without being burdened with the task of correcting every little detail. If you require this of your child he/she will learn very quickly not to write "too" much. Excessive expression then becomes a language lesson punishment.
Remember focus on strengths. What is your child doing correctly that they didn't know six months ago? Are they experimenting with language conventions that they once ignored completely? Informally playing with language is the "Little League" of writing. It's not the major leagues, but it's a great start.
