Today's lucky number is "beaver"

In Japanese there are 3 basic types of verbs. The first type are verbs that end with an "u" sound like iku hanasu and shinu (to go, to speak, to die). The second type are verbs that end with a "ru" as in taberu and ageru (to eat, to give). The last verb type is for irregulars which consists of suru and kuru (to do and to come).

The above are all examples of what is called the dictionary form of a verb. This is also a more colloquial way of speaking. When conjugating these verbs its just a matter of changing the end of it. For type 1 the "u" is changed, for type 2 the "ru" is changed and irregulars have their own rules.
-私はバーに行く。
watashi ha baa ni iku
I am going to the bar

One way to conjugate the verbs is to put them into their long forms. The long form is more polite then regular dictionary form. For type 1, replace the "u" with an "imasu". Iku becomes ikimasu, hanasu becomes hanashimasu, and shinu becomes shinimasu. Type 2, just drop the "ru" all together and put masu at the end. Taberu becomes tabemasu and ageru becomes agemasu. As for the irregulars, just remember that suru becomes shimasu and kuru becomes kimasu.
-私はバーに行きます。
watashi ha baa ni ikimasu
I am going to the bar

When combining two verbs (to say you did "X verb" and "Y verb") the "te" form is used. Type 1 verbs can be a little difficult at first because depending on what's before the "u" determines how it is conjugated. Please consult the chart at the bottom for specific conjugations. Type 2 is easier, replace the "ru" with "te". With irregulars suru becomes shite and kuru becomes kite.
-私はバーに行ってビールを飲みます。
watashi ha baa ni itte biiru o nomimasu
I am going to the bar and drinking a beer

The short past tense form is very similar to the "te" form. The only difference is "te" is now "ta". Pretty simple and doesn't really need anymore explaining.
-私はバーに行った。
watashi ha baa ni itta
I went to the bar

If you want to say you do not do something, the present negative form is used. For type 1 the "u" is changed to "anai". Iku becomes ikanai, hanasu becomes hanasanai, and shinu becomes shinanai. In type 2 the "ru" is replaced with "nai". Taberu becomes tabenai and ageru becomes agenai. For the irregulars, suru becomes shinai and kuru becomes konai.
-私はバーに行かない。
watashi ha baa ni ikanai
I am not going to the bar

The past negative form is used for when you want to say you did not do something. Type 1, "u" becomes "anakatta". Iku: ikanakatta, hanasu: hanasanakatta, and shinu: shinanakatta. Type 2, "ru" is replaced with nakatta. Taberu: tabenakatta, ageru: agenakatta. Irregulars; suru: shinakatta, kuru: konakatta
-（昨日）私はバーに行かなかった。
(kinou) watashi ha baa ni ikanakatta
I did not go to the bar (yesterday)