Using こと、もの

This is how you say 'thing'

Koto - intangible things

いいはありません。 ii koto wa arimasen. There isn't anything good.

大事なを教えます。 daiji na koto o oshiemasu. I will tell you an important thing.

昨日のはすみませんでした。 kinou no koto wa sumimasen deshita. I am sorry about what happened yesterday. (yesterday's thing)

Mono - tangible things

その黒いものは猫かなあ。 sono kuroi mono wa neko kanaa. I wonder if that black thing is a cat?

おいしいものが食べたい oishii mono ga tabetai. I want to eat something good.

One useful phrase using koto is:

どういうこと?
dou iu koto?
What is the meaning of this?

This phrase is used whenever the listener isn't sure of the motive of the speaker.