People often mix their tenses or use the wrong verb form when speaking. Although these errors may be overlooked in conversation, they are painfully evident in written communication. They often confuse the reader and affect the tone of the message.
The present tense is used to express an action or to state a fact that is occurring at the present time. The past tense is used to express action or to help make a statement about something that occurred in the past and has not continued into the present.
English has six basic tenses: present, past, future, present perfect, past perfect, and future perfect.