Pay attention to punctuation, especially to the correct use of commas and periods. Learn the rules of both. And if you are not sure, read your sentence aloud in your normal speaking voice. When your voice makes a natural pause, you probably need a comma. If you need to take a breath, take a longer pause, and you have completed one thought, a period is most likely in order.

While a semicolon (;) is not a punctuation that is used very frequently, it is a good idea to learn the rules for that as well; it will add variety to your writing.

These three punctuation marks regulate the flow of your thoughts, and their misuse or lack of use can make your text confusing even if you are using the right words.