Verbs: polite forms (ます, ません, ました, ませんでした) and ます-stem endings (ましょう, たい, はじめる, おわる, つづける, ながら, に for purpose)

Mastering Japanese Verbs: Polite Forms and ます-Stem Endings

Welcome to your complete revision guide for GCSE Japanese verb conjugations! Verbs are the engine of every Japanese sentence. In this guide, you will master the standard polite forms (ます, ません, ました, ませんでした) and discover how removing -masu leaves behind the versatile ます-stem—a golden key that unlocks powerful endings for invitations, desires, compound actions, and simultaneous activities.

Don't worry if Japanese verb endings seem tricky at first. Once you learn the step-by-step patterns, building natural, high-scoring sentences for your speaking and writing exams becomes simple!

1. Verb Groups and the Golden Rule: Finding the ます-Stem

Before adding polite endings or special suffixes, you need to find the verb stem (known in Japanese grammar as the Ren'yōkei). All Japanese dictionary-form verbs fall into three clear groups:

Group 1: U-verbs (Godan Verbs)

These verbs end in an ~u sound in dictionary form. To find the stem, shift the final ~u vowel sound to an ~i sound.
• 飲む (nomu / to drink) \(\rightarrow\) stem: 飲み (nomi-)
• 行く (iku / to go) \(\rightarrow\) stem: 行き (iki-)
• 読む (yomu / to read) \(\rightarrow\) stem: 読み (yomi-)
• 書く (kaku / to write) \(\rightarrow\) stem: 書き (kaki-)

Group 2: Ru-verbs (Ichidan Verbs)

These verbs end in ~る (-ru), usually preceded by an -i or -e vowel sound. To find the stem, simply drop the る.
• 食べる (taberu / to eat) \(\rightarrow\) stem: 食べ (tabe-)
• 見る (miru / to watch/see) \(\rightarrow\) stem: 見 (mi-)
• 起きる (okiru / to wake up) \(\rightarrow\) stem: 起き (oki-)

Group 3: Irregular Verbs

There are only two irregular verbs you need to memorise for GCSE Japanese:
• する (suru / to do) \(\rightarrow\) stem: し (shi-)
• 来る (kuru / to come) \(\rightarrow\) stem: き (ki-)

Key Takeaway: The ます-stem is whatever remains when you remove -masu from the standard polite verb (e.g. tabe- from tabemasu, iki- from ikimasu).

2. Foundation Tier: Standard Polite Forms (丁寧語 - Teineigo)

Polite verb forms are used in standard everyday conversation and GCSE exam tasks to show respect and natural fluency.

The 4 Core Tense Endings

Attach these four endings directly to your verb stem:

1. Present / Future Affirmative: [Stem] + ます (masu)
Meaning: do / will do
• 日本語を話します。 (Nihongo o hanashimasu. — I speak / will speak Japanese.)
• 明日、学校へ行きます。 (Ashita, gakkō e ikimasu. — I will go to school tomorrow.)

2. Present / Future Negative: [Stem] + ません (masen)
Meaning: do not / will not do
• 肉を食べません。 (Niku o tabemasen. — I do not eat meat.)
• 今週末は出かけません。 (Konshūmatsu wa dekakemasen. — I will not go out this weekend.)

3. Past Affirmative: [Stem] + ました (mashita)
Meaning: did
• 昨日、本を読みました。 (Kinō, hon o yomimashita. — I read a book yesterday.)
• 七時に起きました。 (Shichiji ni okimashita. — I woke up at 7 o'clock.)

4. Past Negative: [Stem] + ませんでした (masendeshita)
Meaning: did not do
• 朝ごはんを食べませんでした。 (Asagohan o tabemasendeshita. — I did not eat breakfast.)
• 宿題をしませんでした。 (Shukudai o shimasendeshita. — I did not do my homework.)

Asking Questions

To turn any polite verb into a question, simply add the question particle か (ka) at the very end. No question mark is strictly required in Japanese, though it is often included in modern writing.
• 映画を見ますか。 (Eiga o mimasu ka. — Will you watch a film?)

Key Takeaway: Always check your time words! Pair past time markers like kinō (yesterday) with ました or ませんでした, and future words like ashita (tomorrow) with ます or ません.

3. Foundation Tier: Useful ます-Stem Endings

Suggestions and Invitations: ましょう and ましょうか

You can turn any verb stem into an invitation or an offer to help:

• [Stem] + ましょう (mashō) \(\rightarrow\) "Let's do [action]"
Example: 一緒に行きましょう。 (Issho ni ikimashō. — Let's go together.)

• [Stem] + ましょうか (mashō ka) \(\rightarrow\) "Shall we do [action]?" or "Shall I do [action]?"
Example 1 (Suggestion): お昼ご飯を食べましょうか。 (Ohirugohan o tabemashō ka. — Shall we eat lunch?)
Example 2 (Volunteering): 手伝いましょうか。 (Tetsudaimashō ka. — Shall I help you?)

Expressing Desires: たいです (Foundation Tier)

To say what you want to do, add たいです (tai desu) to the stem.
• 日本へ行きたいです。 (Nihon e ikitai desu. — I want to go to Japan.)
• ジュースを飲みたいです。 (Jūsu o nomitai desu. — I want to drink juice.)

Tip: You can mark the object of a ~tai sentence with either を or が (e.g. ocha o nomitai desu or ocha ga nomitai desu).

4. Higher Tier: Advanced ます-Stem Endings

Full Conjugation of Desires: ~たい as an い-Adjective

At Higher Tier, you must be able to express what you didn't want to do, or what you don't want to do right now. Important: ~tai conjugates exactly like an い-adjective!

• Present Affirmative: [Stem] + たいです (~tai desu / want to)
Example: 寿司を食べたいです。 (Sushi o tabetai desu. — I want to eat sushi.)

• Present Negative: [Stem] + たくないです (~takunai desu) or たくありません (~taku arimasen / do not want to)
Example: どこにも行きたくないです。 (Doko ni mo ikitakunai desu. — I do not want to go anywhere.)

• Past Affirmative: [Stem] + たかったです (~takatta desu / wanted to)
Example: 先生に会いたかったです。 (Sensei ni aitakatta desu. — I wanted to meet the teacher.)

• Past Negative: [Stem] + たくなかったです (~takunakatta desu / did not want to)
Example: 勉強したくなかったです。 (Benkyō shitakunakatta desu. — I did not want to study.)

Purpose of Motion: [Stem] + に + Motion Verb

Use this structure to express going, coming, or returning somewhere in order to do an action.

Pattern: [Place] へ / に + [Verb Stem] + に + [行く / 来る / 帰る]
• 映画を見に行きます。 (Eiga o mi ni ikimasu. — I am going to see a movie.)
• 図書館へ本を借りに行きました。 (Toshokan e hon o kari ni ikimashita. — I went to the library to borrow books.)
• 家へ昼ご飯を食べに帰ります。 (Ie e hirugohan o tabe ni kaerimasu. — I am returning home to eat lunch.)

Compound Aspect Verbs: はじめる, おわる, つづける

Attach these helping verbs directly to the verb stem to describe the stage of an action. They conjugate as Group 2 verbs.

• [Stem] + はじめる (hajimeru) \(\rightarrow\) To start / begin doing
Example: 去年、日本語を勉強しはじめました。 (Kyonen, nihongo o benkyō-shihajimemashita. — I started studying Japanese last year.)

• [Stem] + おわる (owaru) \(\rightarrow\) To finish doing
Example: 本を読みおわりました。 (Hon o yomi-owarimashita. — I finished reading the book.)

• [Stem] + つづける (tsuzukeru) \(\rightarrow\) To continue / keep on doing
Example: ピアノを練習しつづけます。 (Piano o renshū-shitsuzukemasu. — I will continue practicing the piano.)

Simultaneous Actions: [Stem] + ながら (While doing...)

When one person performs two actions at the exact same time, use ながら (nagara).
Rule: Attach nagara to the secondary action's stem. The primary/main action verb comes at the end of the entire sentence.

• 音楽を聞きながら、宿題をします。 (Ongaku o kikinagara, shukudai o shimasu. — I do my homework while listening to music.)
• テレビを見ながら、ご飯を食べました。 (Terebi o minagara, gohan o tabemashita. — I ate a meal while watching TV.)

Key Takeaway: ながら requires the same person to be performing both actions. The verb at the end determines the overall tense of the sentence.

5. Common Pitfalls and Examiner Advice

Examiners regularly note recurring errors in GCSE Japanese papers. Make sure to avoid these top traps:

1. Attaching Endings to the Dictionary Form Instead of the Stem
• Incorrect: *行くたいです (ikutai desu) or *食べるながら (taberunagara)
• Correct: 行きたいです (ikitai desu) and 食べながら (tabenagara)
Always remember to drop the ~u sound or remove ~ru first!

2. Wrong Negation for ~たい
• Incorrect: *行きたません (ikitamasen)
• Correct: 行きたくないです (ikitakunai desu) or 行きたくありません (ikitaku arimasen)
Remember: ~tai behaves like an い-adjective, not a standard verb.

3. Tense Conflicts with Time Words
• Incorrect: *明日、日本へ行きました (Ashita, Nihon e ikimashita — "Tomorrow, I went to Japan")
• Correct: 明日、日本へ行きます (Ashita, Nihon e ikimasu — "Tomorrow, I will go to Japan")
Double-check that your time marker (past vs future) matches your final verb tense perfectly.

4. Missing the Purpose Particle に
• Incorrect: *本を買いを行きます (hon o kai o ikimasu)
• Correct: 本を買いに行きます (hon o kai ni ikimasu — I go to buy a book)
The action stem must be followed by the particle に before motion verbs like ikimasu, kimasu, and kaerimasu.

5. Subject Mismatches with ながら
Do not use nagara if two different people are doing things simultaneously (e.g. "While my mother was cooking, I was sleeping"). ながら is strictly reserved for one subject multitasking!

6. Quick Revision Summary Table

Keep this mental checklist ready for your exam revision:

• Polite Present / Future: [Stem] + ます / ません
• Polite Past: [Stem] + ました / ませんでした
• Invitations / Suggestions: [Stem] + ましょう / ましょうか
• Desires (Present): [Stem] + たいです / たくないです (or たくありません)
• Desires (Past): [Stem] + たかったです / たくなかったです
• Purpose of Movement: [Stem] + に行きます / 来ます / 帰ります
• Aspect: [Stem] + はじめます (start), おわります (finish), つづけます (continue)
• Simultaneous Action: [Stem] + ながら, [Main Clause Action]