に followed by nouns, what is its usage?

Question

Most of the usages of に I've seen have it directly followed by a verb directly attached to it. (The location of existance にある/にいる, The action objective e.g 私は電車に乗りました, etc)

I know there are some that don't directly have に follow a verb, but its still heavily reliant on a verb (私は六時に家を出る)

However, に can also be used when there are no verbs in the sentence

私に必要です Or 私には必要です

• I interpret (at least the first sentence) as [smth] is essential to [me] or 私*

I (somewhat) get the fact that に and には mean kinda different things and are to be differentiated, so i will just refer to the first sentence.

What usage does the に fall into here? Is there a certain way it gets applied in any sentence with only a noun/ adjective (as in it gets used the same way/ means the same thing)

Other maybe-related examples i found

タバコは体に悪い。 The way i see it (i guess) is that the に marks that tabacco is 悪い towards/ for the body/体. But why can't we use something like が here?

私に何か用ですか。 I guess this sentence works in a similar way to the 必要 one, labelling 私 as "What will i use/ be in use for me"

Sorry if this seems like an obvious question, but im genuinely stumped.

(Edited to explain how i see it)

Answer 1

As I said in my comment, the particle に can be rendered as in, on, at, to or for. It depends on the context which you’ll use.

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にある/にいる identify where something (ある) or someone (いる) is. Lest you be confused by my parentheses here ある means is for nonanimate things (hence something); いる means is for living things, not just people (as someone might imply). In either case, ある/いる only mean is in the sense of location in space.

For example, に shows where something is. Here we’re talking about an animate object, a cat.

ねこは家にいる
The cat is in the house.

Here’s an example with an inanimate object, a book.

本はつくえの上にある
The book is on the desk.

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Let’s look at some of the examples you posted.

私は電車に乗りました。
I got on the train.

Here に shows what you got on or in to ride someplace.

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タバコは体に悪い
tobacco is bad for your body

Here に is best rendered as for

In a comment you asked why you couldn’t use が here. First, タバコは体が悪い, just doesn’t make sense. To see this a bit consider omitting talking about tabacco

体が悪い

would be saying

The body is bad

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Your next example involved an expression of time. In time expressions に is usually rendered as at.

私は六時に家を出る
I leave the house at six

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As for

私に必要です

This just means (literally)

It’s necessary for me.

or (more loosely but depending on context)

It’s important to me.

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Your last example is somewhat idiosyncratic from the point of view of English and depending on your familiarity with other languages that have similar constructs, it may or may not come easily to you.

私に何か用ですか。

Generally this might be rendered fluently as

Do you need me for anything?

where the for anything is how I’m translating 何か; it has nothing to do with the particle に here. The わたしに part is just translated as me.

But this translation obscures what’s happening in the Japanese because in English this is the most natural way to render this particular type of question.

However a more strictly literal translation might make the grammar of this a bit more clear

Is there some kind of need for me?

Basically what you have here is the idiomatic expression

何か用ですか

This is just the standard way of asking, “is there something I can do for you?”

You can modify this form to express different but related ideas. For example, if you said something like

この本に何か用ですか

you be asking “do you have some kind of need (intended use) for this book?”

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As you can see, you selected a diverse variety of uses for に. In a Japanese language class, each of these might be handled in separate lessons.

Answer 2

I want to offer a different approach to the question, because there seems to have been a misconception here. Particles like に don't really care what they're followed by.

Most of the usages of に I've seen have it directly followed by a verb directly attached to it.... I know there are some that don't directly have に follow[ed by] a verb, but its still heavily reliant on a verb

Consider in English:

"I give a ball to the dog."

"I give the dog a ball."

Either way, there are clearly three participants in this action. They can't all be adjacent to the verb, but this doesn't cause a problem.

Similarly in Japanese. The case particles が, に, を, で come after a noun that they're marking, and indicate the role that this noun plays for a corresponding predicate (normally a verb, sometimes an い-adjective). They don't inherently restrict what comes after, except that there should be a predicate they correspond to. Some specific situations allow for implying/omitting that predicate, but there are no such examples here.

Back to English: in these examples, "the dog" is grammatically an indirect object. The direct object of "to give" is the thing that changes ownership; the indirect object is the recipient - that's all baked in to the meaning of the verb. On the other hand, I could say "I reward the dog with a treat", and now the recipient is the direct object.

We can also see that English has many strategies for marking an indirect object: by relying on word order, or by using a variety of different prepositions.

In Japanese, に is most readily explained as a generic marker for an indirect object. There are places where that model will break down, but only when we try to explain it from an English point of view. で is related to に, both etymologically and in its use/meaning; the distinction is out of scope here.

However, に can also be used when there are no verbs in the sentence

These examples have a verb. Or else, how did you understand です?

必要です is analyzed two different ways:

1. だ・です is simply an inflection for nouns that turns them into verbs. In this model, 必要です is just the verb "to be 必要". Thus, the unspecified thing is 必要 for you.

2. です is understood as a contraction of であります, or perhaps でございます; similarly だ as simply である. Either way, this makes it a combination of the case particle で (which is therefore marking the previous noun: in this case, 必要) and... a verb that doesn't quite match English, but in this case is probably best rendered "to exist". Thus, the unspecified thing exists 必要-ly, for you - it is in such a state, that it is 必要 for you.

But either way, there is a verb there, and 私 plays its に role.

タバコは体に悪い。 The way i see it (i guess) is that the に marks that tabacco is 悪い towards/ for the body/体. But why can't we use something like が here?

Now we have an example using an い-adjective for the predicate instead of a verb. But this is really the same thing, because Japanese doesn't really have adjectives, depending on how you look at it.

タバコ, marked as a topic (what we're talking about), is also implied to be a grammatical subject (which would otherwise be marked with が, but is normally omitted here). We can't say 体が because that would replace タバコ as the subject (subject and topic may differ). In English, something like "when it comes to tobacco, the body is bad." (English doesn't explicitly mark topics, and the interpretation is ambiguous - but all the options are nonsense in this case.) The に marks 体, not タバコ. The sentence already told us that tobacco is bad; 体に tells us how it's bad - i.e. who or what is affected by its badness. We can't use を, either, for the same reason we can't say "tobacco is bad you" in English (without the "for").

Re 私に何か用ですか, anything I could say would be redundant with the other answer.