Short Form for Verbs
When explaining the present short form for verbs, point out to students that the affirmative present is the same as the dictionary form. So, 食べる (taberu) is also 食べる in the affirmative present short form. The negative present forms are a little more difficult. Explain to students that the endings change depending on whether a verb is a ru-verb or a u-verb.
Start with ru-verbs: explain that the final る (ru) is dropped, then ない(nai) is added. With u-verbs, the u is taken off, then -anai is added. Point out there are three verbs that have different negative present forms: する(しない) (suru [shinai]), くる(こない) (kuru [konai]), and ある(ない) (aru [nai]).
Once the different negative present forms have been explained, pass out a worksheet that tests the students' ability to match the affirmative to the negative forms. On the left side, list ru-verbs, u-verbs and irregular verbs, such as: 食べる, 書く(kaku), 話す(hanasu), 待つ(matsu), 死ぬ(shinu), 読む(yomu), 作る(tsukuru), 泳ぐ(oyogu), 呼ぶ(yobu), 買う(kau), する, くる and ある. On the right side, list the negative present forms: 食べない(tabenai), 書かない(kakanai), 話さない(hanasanai), 待たない(matanai), 死なない(shinanai), 読まない(yomanai), 作らない(tsukuranai), 泳がない(oyoganai), 呼ばない(yobanai), 買わない(kawanai), しない, こない and ない. Shuffle one column and ask the students to draw an arrow from the affirmative to the negative. Then, ask then to underline the endings.