The simple present tense describes actions and states of being that are (or are not) taking place at the current time. Lessons that focus on this tense describe the formation of the tense: generally, the verb doesn't change at all from its basic form unless you're writing in the third-person singular (he, she or it as the subject, for example). Verbs that end in "y" drop that letter and instead end in "-ies." The verb "to be" is irregular in all of its forms and requires memorization.
Example: for the verb "to try":
I try...you try...he TRIES...we try...you (plural) try...they try
The simple past tense focuses on events and states of being that happened at some point in the past, but are not happening now. Lessons about this tense also teach proper formation. For regular verbs, the usual change is to add "-ed" or "-d." Verbs that end in "y" change as they did with present tense, except that they will now end in "d."
Example with the verb "end":
The movie ends at midnight (present)
The movie ended at midnight (past)
Irregular verbs, however, can be frustrating for the English language learner, because of the inconsistencies. For example, the verb "send" looks like it should read "sended" in the past, to be consistent with "end." However, "send" becomes "sent" in the past. There are many irregular verb formations in the past tense that simply require memorization, and many lessons over the past tense involve learning lists of verb forms.
Sometimes the simple past and present don't describe an event's occurrence with enough force, which is where the emphatic form comes in. Using the helping verbs "do" and "does" in the present tense, and the helping verb "did" in the past tense, the emphatic can form a powerful rebuttal or initial statement.
Examples:
Child: I cleaned my room this morning.
Mother: I saw a messy bed in there. Are you sure?
Child: I did clean my room!
Boyfriend: I want to rent "Titanic" with you. It's such a great love story.
Girlfriend: Really? Wouldn't you rather watch "Transformers" or "The Rock"?
Boyfriend: No! I do want to watch "Titanic" again.
In the progressive, or continuous construction, the main verb will end in "-ing," and a being verb will serve as the helping verb. This construction expresses an action or state of being that, instead of happening at one point in time, was ongoing and may still be happening. Lessons that teach these constructions focus on examples like these:
We are eating dinner right now (present).
They were fighting all evening long (past).