1. By attaching the phrase "~ koto ga dekiru (~ことができる)" after the basic form of the verb, for example :
- Nihongo o hanasu koto ga dekiru / 日本語を話すことができる/ (I) can speak Japanese.
- kanji o kaku koto ga dekiru / 漢字を書くことが出来る。/ (I) can write kanji
note :
"~ dekiru (~できる)" can also be directly attached to a noun, if a verb is closely associated with its direct object. with previous sample
- nihongo ga dekiru / 日本語ができる。/ (I) can (speak) Japanese.
- kanji ga dekiru / 漢字ができる。 / (I) can (write) kanji.
2. By potential form of the verb.
hanasu, 話す - hanaseru、話せる
kaku、書く - kakeru、書ける
The potential form indicates that something is possible but no actual action is actually taken
how to make potential verb, look at picture below
for Group 1, from basic from or dictionary from, erase the last letter (picture above blocked with Grey color, it's usually u group like : u, tsu, ku, mu, nu, fu, ru) than change with e group in the same row than plus with ru, for example kaku, erased ku change with ke than plus with ru, so it become kakeru.
for Group 2, for dictionary from, just plus with rareru
for Group 3, suru will change with dekiru, and kuru with korareru