Two big things - もの (mo-no) and こと (ko-to)

The English word "thing" has two things when translated to Native Japanese. One is a material "thing" もの (mo-no) and the other is abstract "thing"　こと (ko-to) . We have the word ものごと (mo-no-go-to), which is もの (mo-no) + こと (ko-to) and means very roughly "everything".

"Thing" is a very general word and has many different meanings. The most similar word would be "object". "Object" is more specific than "thing".  Again "thing" is a very general word as it has at least two general meanings in  Native Japanese - もの (mo-no) and こと (ko-to). The problem is that もの (mo-no) and こと (ko-to) are very commonly and frequently used in every day life (which means that there are countless examples to check) and the Japanese people differentiate these two words unconsciously, which means that it is very difficult to analyze the unconscious uses of the words, although worth challenging.

1) Visible もの (mo-no) and Invisible こと (ko-to)

もの (mo-no) is a thing which generally can be seen and こと (ko-to) is a thing which  generally cannot be seen. Let's look at some examples.

You should keep an important thing in a safe. (Note 1)
This thing can be seen then in Native Japanese  もの (mo-no) is used
たいせつなものは金庫にしまっておくべきだ。 ...... (ta-i-se-tsu-na-mo-no-wa .......)

The important thing is ......
This thing cannot be seen then in Native Japanese こと (ko-to) is used
たいせつなことは ...... (ta-i-se-tsu-na-ko-to-wa .......)

As said above "things in Native Japanese" are not so simple.

2)  もの (mo-no) as a material object and こと (ko-to) as an event


We can say ＜ものをたべる (mo-no-o-ta-be-ru)＞ or ＜to eat  もの (mo-no)＞  but cannot say ＜ことをたべる (ko-to-o-ta-be-ru)＞ or ＜to eat  こと (ko-to)＞.

We can say ＜ことがおきる (ko-to-ga-o-ki-ru）＞ or ＜こと (ko-to) happens＞ but cannot say ＜ものがおきる(mo-no-ga-o-ki-ru）＞or ＜もの (mo-no) happens＞.

3) Indefinite  もの (mo-no) and Definite こと (ko-to)  

As shown in the above examples, もの (mo-no) is used as an indefinite object (any) while こと (ko-to) usually implies a definite object (the xxxx, xxxx which). The following words support that もの (mo-no) is used as an indefinite object (any).

ものうり (mo-no-u-ri; 物売り)  -  a vender (a person selling things)
ものおき (mo-no-o-ki: 物置)  -  a store room (a place for storing things)
ものおぼえ(mo-no-o-bo-e; 物覚え)  -  an ability of remembering  things
ものおもい(mo-no--o-mo-i; 物思い)  -  pondering things
ものかき(mo-no-ka-ki; もの書き)  -  a person writing things
ものがたり(mo-no-ga-ta-ri; 物語り)   -   telling things
ものしり(mo-no-shi-ri; 物知り)  -  a person knowing things
ものとり(mo-no-to-ri; 物取り) -  a person stealing things
ものもち(mo-no-mo-chi; 物持ち)-  a person having things

All these mo-no's are very general and cannot be replaced with こと (ko-to). On the other hand こと (ko-to) is usually used when indicating (not showing as こと (ko-to) is usually not seen) something which is already specified either explicitly or implicitly.

もの (mo-no) + adjective

ものうい (mo-no-o-u-i)  
ものおそろしい (mo-no-o-so-ro-shi-i)  -  (not sure about what but) horrible, frightening
ものがなしい (mo-no-o-ga-na-shi-i) -  (not sure about what and why but) sad
ものさびしい (mo-no-o-sa-bi-shi-i)  -  (not sure why but) lonly
ものしずか (mo-no-o-sh-zu-ka)   -  (somehow) silent
ものたりない (mo-no-o-ta-ri-na-i)  -  (not sure of what but) insufficient

もの (mo-no) adds "not sure" feeling (indefinite) to the original adjective.

もの (mo-no) has also has generalization function of a thing, either a material object or non-material object.

くるま (ku-ru-ma; 車) というものは (to-i-u-mo-no-wa) ......
 Things about cars are .......
 いのち (i-no-chi: 命) というものは (to-i-u-mo-no-wa) ......
Things about life are .......

On the other hand,  こと (ko-to) has 'objectization’ function of a verb or action. This is similar to the English infinitive.

みるということは (mi-ru-to-i-u-ko-to-wa; 見る) -  To see is .....
きくということは (ki-ku-to-i-u-ko-to-wa; 聞く) -  To hear is .....
たべるということは (ta-be-ru-to-i-u-ko-to-wa; 食べる) -  To eat is .....
おもうということは (o-mo-u-to-i-u-ko-to-wa; 思う) - To think is ......
するということは (su-ru-to-i-u-ko-to-wa)  - To do is .....

The last するということは (su-ru-to-i-u-ko-to-wa) differs from することは (su-ru-ko-to-wa), which means "the thing to do is .......".

Although もの (mo-no) is used as an indefinite object (any) while こと (ko-to) usually implies a definite object there are many exceptions.

ものがものだけに（なので）...... (mo-no-ga-mo-no-da-ke-ni (na-no-de)......)
Literally - As the thing is the thing ......
ことがことだけに（なので）...... (ko-to-ga-ko-to-da-ke-ni (na-no-de)......)
Literally - As the thing is the thing ......

You may be confused. This is analogous (in terms of sentence structure, not the meaning) to "This is it." Although が(ga) is used もの (mo-no) and こと (ko-to) are the definite things in these uses. Still, ものがものだけに shows some ambiguity while ことがことだけに shows some definiteness.


(Note 1)
Is is important to know that there is no Native Japanese adjective for "important". I tried to find but found one but not one word - こころすべき (ko-ko-ro-se-be-ki) which means literally "should do heart" or something like "should pay attention" .
たいせつ (ta-i-se-tsu) seems Native Japanese but it is not.  たいせつ (ta-i-se-tsu) is 大切 in Chinese characters and pronounced 'da-qie'. たい (ta-i) is similar to 大(da). But せつ (se-tsu) is quite different from 切 (qie) and and 大切 cannot be found in Chinese. And even せつ (se-tsu) is independently used such as せつに (se-tsu-ni; 切に)  or "sincerely". So it seems たい (ta-i) is Chinese origin and せつ (se-tsu) is Native Japanese - this combination is common in Japanese. However せつ (se-tsu) is highly likely Chinese origin and deeply set into Japanese. See below.

季節 （きせつ）　(ki-se-tsu)  -  季节 (ji-jie)
接続（せつぞく）(se-tsu-zo-ku) - 连接 (lian-jie)

だいじな (daiji-na, 大事な) is another Chinese origin word for "important". The original Chinese meaning of  だいじ (daiji, 大事) was and is "a big thing" literally and more often "a big incident". And it is a noun not an adjective. To change it to an adjective in Japanese you must add the adjective suffix な (na) to the noun. The original Japanese meaning may have been "of a big incident". This has been changed to the meaning of importance (noun). Or as Native Japanese of "a big thing" or "a big incident" is おおごと (o-o-goto) already existed so だいじ (daiji, 大事) was used differently form おおごと (o-o-goto). おおごと can be written by using Chinese Characters as 大事 (pronounced as "o-o-goto"). So in Japanese 大事 has two different meanings and pronunciations.

Native Japanese: 大事 (pronounced as "o-o-goto")  - a big thing,  a big incident

 Chinese origin: だいじ (daiji, 大事)- importance (noun),  だいじな (daiji-na, 大事な) - important (adj)

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