Past and negative

Every polite verb you have met so far has been sitting in one corner of a small square. The ending ます is only one of four, and the other three are just as regular: swap the ending and you have moved the sentence into the negative, into the past, or into both at once. Nothing else in the sentence changes. The particles stay put, the word order stays put, and the verb still comes last.

The four forms

Take the ます off a verb and you are left with the stem, the part that never changes. 読よみます has the stem 読よみ, and every polite form of that verb is the stem plus one of four endings.

That is the whole system, and it works for every verb in the language without exception. Once you can hear the stem, you can produce all four forms of a verb the first time you meet it.

Notice the top form is labelled non-past rather than present. Japanese draws its line between what has already happened and what has not, so 読よみます covers what you do habitually and what you will do tomorrow alike. Only ました commits you to something finished.

Saying no: ません

The negative ending replaces ます entirely. There is no extra word for "not" and no helper verb like English "do".

私わたしは肉にくを食たべません watashi wa niku o tabemasen I do not eat meat

たなかさんはコーヒーを飲のみません tanaka-san wa koohii o nomimasen Tanaka does not drink coffee

今日きょうはテレビを見みません kyou wa terebi o mimasen I am not going to watch television today

The last one shows the non-past doing future work. Nothing in the verb says tomorrow or today; the time word does that, and the verb only tells you the thing has not happened yet.

Saying it already happened: ました

For the past, the ending is ました. Japanese leans on time words much more heavily than English does, and a sentence usually opens with one.

昨日きのう本ほんを読よみました kinou hon o yomimashita I read a book yesterday

先週せんしゅう映画えいがを見みました senshuu eiga o mimashita I watched a film last week

今朝けさ朝あさごはんを食たべました kesa asagohan o tabemashita I ate breakfast this morning

Both at once: ませんでした

The past negative is the longest ending in beginner Japanese and the easiest to build, because it is simply the negative with でした stuck on the end. If you can say ません you can say ませんでした.

昨日きのうは晩ばんごはんを食たべませんでした kinou wa bangohan o tabemasen deshita I did not eat dinner yesterday

先週せんしゅうはてがみを書かきませんでした senshuu wa tegami o kakimasen deshita I did not write any letters last week

今朝けさ新聞しんぶんを読よみませんでした kesa shinbun o yomimasen deshita I did not read the newspaper this morning

Any of the four forms takes か on the end to become a question, exactly as the plain ます form did.

昨日きのう映画えいがを見みましたか kinou eiga o mimashita ka Did you watch a film yesterday?

The same square for です

です has its own set of four, and they are less tidy, so they are worth learning as fixed items rather than as a pattern.

The negative has a more formal twin, ではありません, which is what you write and what you say in a speech or a report. じゃ is simply ではrun together in speech, and it is what you will hear in ordinary conversation. Both are polite; ではありません is the stiffer of the two.

あの人ひとは学生がくせいじゃありません ano hito wa gakusei ja arimasen That person is not a student

昨日きのうは休やすみでした kinou wa yasumi deshita Yesterday was a day off

たなかさんは先生せんせいじゃありませんでした tanaka-san wa sensei ja arimasen deshita Tanaka was not a teacher

The one trap here is the past. でした is the past of です, and there is no such word as ですた. Equally, the past negative is built on the negative, never on でした, so じゃありませんでした is right and でしたじゃありません is not a Japanese sentence at all.

Answering with the form you were given

A short answer in Japanese repeats the verb rather than borrowing a helper the way English borrows "did". Asked 食たべましたか, you answer はい、食たべました or いいえ、食たべませんでした. There is no equivalent of "yes, I did", so the habit of echoing the verb in the right form is worth building now, while the verbs are short.

Vocabulary

Four endings and one irregular verb have roughly doubled what you can say, because every verb you already knew now works in four tenses instead of one. The next step is to describe the things in your sentences rather than only name them, which means adjectives, and Japanese has two kinds.