I'd like to say “Tomorrow is Monday”. Is it correct for me to say 「あしただげつようび」? Or is there simply no particle at all?

  • Your sentence is missing a verb. And a topic (hint). Commented Sep 27, 2013 at 2:53
  • 6
    Unfortunately, your question is about such fundamental grammar that it's unclear if you've learned enough Japanese yet to make sense of an answer. We all have to start somewhere, so please don't take this as discouragement, but it would seem you could benefit from a little bit more textbook reading before trying to formulate questions. The correct way to say the sentence you are asking about is あした は げつようび だ. I hope that helps you go forward in figuring out what does.
    – Questioner
    Commented Sep 27, 2013 at 4:28

1 Answer 1


No, you can't use だ that way.

Here's what you're trying to do:

あした   = tomorrow
だ     = is
げつようび = Monday

Unfortunately, that doesn't work. Why not?

  • Japanese grammar is different from English grammar. That means you can't put words together the same way in both languages.
  • Japanese vocabulary is different from English vocabulary. That means that words in one language don't always correspond directly to words in the other, either in terms of meaning or usage.

So what can you do?

  1. Stop guessing how to make sentences. Find a textbook, a reference book, or a website, and start learning some correct sentences. You can find lots of these in our Resources for Learning Japanese section. Here are a few in particular:

    Of course, you could also take a class.

  2. Make your own sentences based on the patterns you've learned.

Feel free to stop reading here. Go to a store and buy a textbook, or sign up for a class! You'll learn a lot more that way. But because I feel like writing, and because it's educational for me to articulate my thoughts, I'll do my best to answer your question anyway.

A comparison between English and Japanese

To understand what's different between English and Japanese, we first have to understand what's going on in English. Let's take a look at your sentence:

Tomorrow is Monday.

The verb "is" is called a "copular verb". The "copula" part comes from Latin, and it literally means that it joins two things together. When you say "A is B", you're joining A with B somehow. And of course, the copula has a lot of uses in English. Here are a couple important ones:

  • Ascriptive use: B is a trait of A (Cats are nice.)
  • Specifying use: A and B are the same thing (My cat is the one on the left.)

What about Japanese? Does it have something similar? Well, is often described as the copula! And in fact, it does something pretty similar, joining two things together. But there are two big differences:

  1. The copula isn't a verb. It's a kind of suffix.
  2. Japanese word order is totally different!

So you can't just stick where you'd stick is, even though it's pretty similar.


In Japanese, we usually put predicators at the end of a sentence. But wait, what's a predicator? Well, in English, we really only have one type of word that can be a predicator, and that's a verb! But Japanese has three types:

  1. Verb:

    ストアに いく       (sutoa-ni iku)
    go to the store

  2. Noun + copula:

    これは リンゴだ     (kore-wa ringo-da)
    This is an apple

  3. Adjectives:

    そらが うつくしい    (sora-ga utsukushii)
    The sky is beautiful.

The key here is that the predicator comes at the end, no matter which type of word it is. Of course, there's a lot more to say about these examples, and of course I want to focus on the noun + copula combination. But first, we'll have to take a look at some of the other words in these sentences.


You'll notice something about the words ストア, これ, and そら. All three of these are marked with a suffix that tells you what role it plays in the sentence. In example 1, for instance, we've got the suffix に ("to") attached to the noun ストア ("store"):

ストア              (sutoa-ni)
to the store

These suffixes are usually called particles. And when you add one of these suffixes, it makes a new "phonological word". In less technical terms, that means you should pronounce the -ga in sora-ga as though it's part of the same word! Let me repeat this, because it's really important:

   When you pronounce sora-ga, do not pause after sora!

And だ is a special kind of suffix, too. When we add だ to リンゴ ("apple"), we get the predicator リンゴだ ("is an apple"). And again, you can't pause between リンゴ and だ. Phonologically speaking, the combination is a single word! And like all predicators, リンゴだ has to come at the end of the sentence. We can't stick it in the middle.

What about your sentence?

*あしただ げつようび      (*ashita-da getsuyōbi)

Well, there are more things we need to learn before we can fix it, but I'm sure you can see one problem with it now. When you add だ to あした ("tomorrow"), you get a predicator あしただ ("is tomorrow"). And that has to come at the end of the sentence! So by the time you start saying げつようび, your sentence is already over. This is no good.

Instead, we probably want to attach だ to the second word and form the predicator げつようびだ ("is Monday"). So if we do that, your sentence looks something like this:

あした、げつようびだ      (ashita-∅ getsuyōbi-da)

Well, that's still not perfect, but it's an improvement. You could get away with saying this, but it's not quite complete. I put in a ∅ symbol to show where something has been left out. But before I talk about what to add to make it complete, I want to talk about English again.

Subjects and predicates

The terms subject and predicate come from western grammar. The idea is that the predicate says something about the subject. For example, it can say something that the subject is doing (like "goes to the store"), or it can tell us about a trait (like "is green"). Let's look at your sentence:

[ Tomorrow ]subj  [ is Monday ]pred

The subject is "tomorrow". The predicate is "is Monday". That tells us something about the subject, right? Well, that's what predicates do. (Remember, our English predicator is the verb "is". The whole predicate is "is Monday".)

In English, we know that "tomorrow" is the subject because it's a noun and because it's at the beginning of the sentence. We're pretty good at spotting subjects, even though we don't mark them with a suffix in English. So it's easy for us to see what part of the sentence the predicate is acting on.

And in Japanese, we have predicates too. And a predicate contains a predicator, just like in English. The difference is what a predicate acts on. In Japanese, you mark the thing a predicate acts on using a particle. And usually, it's one of these two:

  1. The subject particle が:

    そらが うつくしい    (sora-gasubj utsukushiipred)
    The sky is beautiful.

    Here, そら ("the sky") is the subject, and the predicator うつくしい ("is beautiful") tells us something about it. The sky is beautiful.

  2. The topic particle は:

    これは リンゴだ     (kore-watopic ringo-dapred)
    This is an apple

    Here, これ ("this") is the topic, and the predicator リンゴだ ("is an apple") is a comment on that topic. This is an apple.

In English, both the subject "the sky" and the topic "this" would be expressed grammatically as a subject. So here again, you can see a difference between English and Japanese grammar.

Completing the sentence

Let's go back to your sentence. We saw earlier that あした was missing something:

あした、げつようびだ      (ashita-∅ getsuyōbi-da)

How do we tell whether we should add は or が? Well, unfortunately the difference is too complicated to explain here. And it's notoriously difficult to explain, and controversial to boot, so I'd probably end up explaining it wrong. (Entire books have been written on the subject!) But since you're just starting out, you don't need to worry about that yet. You need to learn some sentence patterns and grammar before you delve too deep into the mystery of は versus が.

So for now, let's just say that we want to add the topic particle は! Let's add that in:

あしたは げつようびだ     (ashita-watopic getsuyōbi-dapred)
Tomorrow is Monday.

And now we've got a complete sentence! Woo hoo! Our predicator げつようびだ ("is Monday") tells us something about the topic あした. We can say that the right half of the sentence is "predicating on" the left half. (And remember, pronounce ashita-wa as one word, and the same goes for getsuyōbi-da! Don't pause!)

So this sentence is done. But remember: textbook, class, or website ;-)

In this answer, * means that the sentence is not grammatical Japanese.

  • Are you suggesting that だ not be called a copula, but rather described as one of three possible predicators? Don't copulae always have predicating functions?
    – Earthliŋ
    Commented Sep 28, 2013 at 12:02
  • 1
    I think that all comes down to how you define "word", and I'm going with "phonological word" here. There's phonological evidence that suffixes like 助詞 and 助動詞 don't form independent words: 1. pitch accent, 2. distribution of nasal g, 3. は becoming wa, and 4. the fact that you can't pause between a word and its suffixes. Since predicator is a syntactic function, and syntax describes relations at the word level or larger, then if だ is a suffix, the smallest unit that can have that function is noun + だ. (I don't object to analyzing it differently, but this is what makes sense to me.)
    – user1478
    Commented Sep 28, 2013 at 12:57
  • I wonder if the だ in だの is etymologically related to the copula..
    – ssb
    Commented Sep 28, 2013 at 13:01
  • Given that だから (and ですので etc.) can appear at the beginning of a sentence, I'm inclined to think that だ etc. are slowly becoming word-like in more than just the syntactic sense. (It is, by the way, a syntactic word like any other clitic.)
    – Zhen Lin
    Commented Sep 28, 2013 at 14:00
  • @ssb 日本語国語大辞典 says yes.
    – Zhen Lin
    Commented Sep 28, 2013 at 14:01

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .