The past form ました

Verb ました verb mashita Did

ました (mashita) is the polite past: 行きます becomes 行きました. Every verb follows the same rule, so there are no irregular past forms to learn.

Level: JLPT N5, beginner
Type: Verb forms
English links: past simple, irregular verbs, present perfect

What it means

To talk about the past, change ます to ました. 食べます becomes 食べました, 行きます becomes 行きました. That is all. Even する and 来る follow the rule: しました, 来ました.

So in the polite form, Japanese has no irregular past. English has more than a hundred common ones: went, ate, saw, bought. Your students meet a problem in English that does not exist in polite Japanese.

ました also covers some things English says with the present perfect. もう食べました is "I've already eaten". And a few common words use the past where English uses the present. わかりました is "I understand" or "Got it", and 疲れました is "I'm tired".

How to build it

Pattern	How it works
～ます → ～ました (食べます → 食べました) tabemasu → tabemashita	Swap the ending. Same rule for every verb.
行きます → 行きました ikimasu → ikimashita	Compare English go → went. No change in the stem here.
します → しました, 来ます → 来ました shimasu → shimashita, kimasu → kimashita	The irregular verbs are regular in this form.

Examples

昨日、宿題をしました。 kinou, shukudai o shimashita. I did my homework yesterday.
週末に京都に行きました。 shuumatsu ni kyouto ni ikimashita. I went to Kyoto at the weekend.
もう朝ごはんを食べました。 mou asagohan o tabemashita. I've already had breakfast.
先生と話しました。 sensei to hanashimashita. I spoke with the teacher.
はい、わかりました。 hai, wakarimashita. Yes, I understand.

How English says it

English uses the past simple: "-ed" for regular verbs, and a special form for irregular ones. "I walked", but "I went", "I ate", "I saw".

English also has the present perfect: "I've eaten", "I've been to Kyoto". Japanese uses ました for many of these, so students must learn when English wants "have" and when it wants the plain past.

Why it can make English hard

Irregular past forms are pure memory work. Students who know ました is always regular may add "-ed" to every verb: "goed", "buyed".
In questions and negatives, English moves the past onto "did". Many students mark it twice: "Did you went?"
One Japanese form covers both the past simple and the present perfect. Choosing between them is hard for years.
Some students say "-ed" as an extra syllable, as in katakana English. "Walked" can come out as three syllables.

Mistakes you will hear

I goed to Kyoto. I went to Kyoto. Polite Japanese has no irregular past, so students make English regular too.
Did you ate lunch? Did you eat lunch? "Did" already shows the past. The main verb goes back to the base form.
I understood. I understand. (or: Got it.) A copy of わかりました. Japanese uses the past here; English uses the present.
I was tired. I'm tired. From 疲れました, said at the end of a long day. The student means now, so English needs the present.

In the classroom

On Monday mornings, ask "What did you do at the weekend?" and nothing else. Students answer in one sentence. Write the verbs on the board in two columns: regular and irregular.
Make a "what Japanese says in the past, English says in the present" list: わかりました, 疲れました, お腹がすきました. Students enjoy the surprise, and it stops a common error.
For "-ed" sounds, sort verbs into three boxes: /t/ (walked), /d/ (played), /ɪd/ (wanted). Only the last one adds a syllable.

Practice

Try each one, then open it to check.

1. Make the past form: 飲みます

Answer: 飲みました

Change ます to ました.
2. Fill the gap: 昨日、映画を見＿。 (I watched a film yesterday.)

Answer: ました

昨日 shows the past, so use the past ending.
3. A student writes "Yesterday I buyed a new bag." Fix it.

Answer: Yesterday I bought a new bag.

"Buy" is irregular. Its past form is "bought".
4. Translate: 疲れました。 (said after work)

Answer: I'm tired.

Japanese uses the past for a state that began earlier. English describes how you feel now.