Hello,
I often see these two terms used seemingly interchangeably, and I was wondering if I was correct in assuming that.
For example, is there a difference the sentences below?
It kind of feels like it’s the difference between “Mr. Tanaka does study” and “Mr. Tanaka studies”, but I don’t really see how that would be a different sentence.
I’m hearing that there is implied direct object within 田中さんが勉強します
-> * 田中さんが(something を）勉強します ->“Tanaka studies (it /fill in the blank/implied within the context)”.
For 田中さんが勉強をします sounds like “Tanaka studies”. This sounds like one of those interchange-able situations for は/が, depending on the emphasis.
Disclaimer: I think this is correct 
So basically, without the を, I’m doing the thing to something? Like in this case, I’m doing a study to Japanese? But since the sentence is structured that way, it is implied that I’m at least doing a study towards something, possibly mentioned earlier?
To put two を in the first example you had, it just doesn’t sound right. Many suru verbs are transitive in nature so makes sense to omit it. But if you want to make it a direct object, I think it give a bit more emphasis that the study is the direct object now.
I suppose to be more literal, this is what I’m hearing below.
毎日田中さんが勉強をします。
Everyday Tanaka studies (Tanaka studies everyday)
If this is a stand alone sentence, I want to hear は as a topic marker. However in context of something else, I think this still works (just adjusts emphasis).
毎日田中さんが(英語を）勉強します。
Everyday Tanaka studies it (English). (Tanaka studies it (English) everyday)
If we literally see Tanaka with an english book (or English has already been implied already), it doesn’t need to be stated again. I threw a 毎日 just to round it out a bit. Do we have to say ‘it’? Probably not and I suppose some translation would say “Everyday Tanaka studies” but there is the grammatical headroom to imply a DO.
DBJG talks a bit about it as well (this is pg 431 if you have it) but not so much.
There is the classic example that uses the implied DO potential (ignoring te+iru):
(私は）魚を食べる= I’m eating fish
魚が食べる= The fish are eating
Then there is the grammatical room to add a DO
魚が（パンを）食べる= The fish are eating bread
For those reasons, that is why I hear ‘it’ or ‘something’ with this structure
You have opened a can of worms, my friend. Imabi does an excellent job explaining the differences between する and をする, する verbs, and when/if to use をする or just する after a noun.
If we put the verb in brackets, your sentences look like this:
In the first sentence, 勉強 is the noun that 田中さん will する.
In the second sentence, 勉強する is the verb that 田中さん will do.
As @s1212z pointed out, する is Japanese’s quintessential transitive verb (conversely, ある is Japanese’s quintessential intransitive verb). In Japanese, the distinction between which verbs are transitive/intransitive is:
Let’s look at the second sentence again:
We have no を in this sentence, which means that what 田中さん will 勉強する is omitted either because it is implied, or because it is unimportant. Anyway, to add what 田中さん is studying in both sentences, we could say:
You’ll notice that both sentences only have one を per verb.
So really, there’s not a whole lot of difference in meaning. But, you can think of [Noun]する as a means of “verbifying” the noun whenever there’s no を directly before する.
* The only “exception” I’m aware of is movement verbs (like 歩く、走る、飛ぶ), which can be used with を. This simply causes the verbs to behave transitively though, which can also happen in English: “Sail” is generally not a transitive verb, but it is still possible to say something like “sail the seven seas” and use it transitively. (“I ran the marathon” is another example of a transitive application of a movement verb.)
This is slightly tangential, but I came across some interesting threads regarding dropping particles for anyone interested. I think many of us have found this to be a frustrating hurdle (
) between textbook “written” and general “spoken” at one point or another.
I wasn’t familiar with Yuta Aoki thread before but he had a nice and simple video lesson on particle dropping along with a stackexchange thread
