Main verbs

A simple sentence has only one verb. For example, in “I write letters” write is the verb. Every complex sentence has a simple sentence at its heart, and the verb in this simple sentence is the main verb. For example, we can make that first sentence more complex by saying, ‘I write letters that you send out’. Write is the main verb here because it applies to the sentence’s subject I. The object of the sentence is ‘letters that you send out’.