The most basic sentence is made up of a subject and an action. So, basically, put a noun and a verb together. The noun or pronoun is the subject and it is performing the action. 2. Be mindful of subject-verb agreement. This rule basically means that, if you have a singular subject, use a verb in its singular form and if you have a plural subject, use a verb in its plural form. Let’s go back to the sentence: The child ran fast. “Child” is a singular noun and the subject so “ran” is a verb in its singular form. There are, however, other rules about the subject-verb agreement that you need to know and this could vary depending on the language you are learning. 3. Learn how to form compound sentences. This is when you use a conjunction to join two sentences with related thoughts together. Compound sentences sound more fluid and native speakers are more likely to use compound sentences instead of multiple short sentences.