A Japanese verb has a dictionary form, usually ending with -MASU.

Hanashimasu.                I speak, I will speak. (present tense)
Hanashimash'ta.             I spoke, I have spoken. (past tense)
Hanashimashoo.              Let's speak, let's talk. 
Hanashite imasu.            I am speaking. (present progressive)
Hanashite imash'ta.         I was speaking. (past progressive)
Hanashite kudasai.          Please speak.

The negative form of a verb is made with VERB+SHIMASEN 

Hanashimasen.               I do not speak, I will not speak.
Hanashimasen desh'ta.       I did not speak. (past negative)
Hanashimash'te imasen.      I am not speaking. (present progressive negative)
Hanashimash'te imasen.      I was not speaking.






                         The -te and -ta forms

As you may have noticed, the -TE form is a gerund form of a verb, while the 
-TA form is the PAST TENSE form of a verb.