[CrimsonNataku]

Originally Posted by Ayame90

Hey, ur confusing me.

Sorry. In Japanese there are various ways to conjugate a particular verb in order to create a sentence with a specific meaning.

In other words, you start with the dictionary form of a verb. It is called this because that is the form of the verb you find in the dictionary. For the sake of making it easier to explain, let's stick with "To close" or shimau.

Once we know the dictionary form of a verb, we can then conjugate it so it means what we want it to mean:

I close the book
Watashi wa hon wo shimaimasu.
I closed the book
Watashi wa hon wo shimaimashita.
I don't close the book
Watashi wa hon wo shimaimasen. (You can also use the informal conjugation which is shimawanai desu)
I didn't close the book
Watashi wa hon wo shimaimasen deshita. (Which you can also say as shimawanakatta desu [informal])

For each different meaning, you need to conjugate the verb differently. The sentences above are examples of the four basic verb conjugations; Affirmative, Past Affirmative, Negative, and Past Negative.

Now, when I said:

Sono hon wo shimatte kudasai.

I was using the "-te" verb conjugation of the verb shimau. "Te" form is usually used as a gentle command. In other words, the sentence means "Please close that book."

Does this help?