⑴ 《 動詞の原形＋ing 》 の形で用いられ，［ ］と訳す。
⑵ ［ ］として用いられる場合は，不定詞で置き換えられる。
① Walking every morning is my habit. ＝To walk every morning is my habit.
② Studying English is interesting. ＝To study English is interesting.
⑶ ［ ］として用いられる場合は，不定詞で置き換えられる。
① My hobby is going to the woods. ＝My hobby is to go to the woods.
② Seeing is believing.＝To see is to believe.
⑷ 動詞の［ ］として用いられる場合
① I like using a computer. ★like, begin, start, loveは，不定詞で置き換えられる。
② Did you enjoy dancing at the party？ ★enjoy, finishは，不定詞で置き換えられない。
⑸ 前置詞の［ ］として用いられる場合
① You are very good at playing tennis. ＝You play tennis very well.
② She is very fond of cooking a cake. ＝She likes cooking a cake very much.
③ The girl went away without saying good-bye.
④ I wash my face before eating breakfast. ＝I wash my face before I eat breakfast.
⑤ I drink tea after having dinner. ＝I drink tea after I have dinner.
⑥ How about going to the movie？
＝Shall we go to the movie？
＝Let’s go to the movie.
① He stopped smoking.
①’ He stopped to smoke.
② I tried eating the fish.
②’ I tried to eat the fish.
③ I remember writing to him.
③’ Please remember to write to him.
④ I forgot visiting her.
④’ I forgot to visit her.
① go shopping
② go swimming
③ go fishing
④ go skiing
⑤ look forward to + ～ing
⑥ cannot help ＋～ing