How to form basic present and past verbs in Japanese

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To form basic present and past verbs in Japanese, the approach depends on whether the verbs are informal (plain) or formal (polite) and on the type of verb.

Present Tense Verb Formation

• The basic present tense in Japanese is often called “non-past” because it can express both present and future actions.
• Informal verbs typically end with “u” sounds like のむ (nomu, to drink).
• Formal verbs end with ます (masu), e.g., 飲みます (nomimasu, drink).
• The verb stem is used before the suffix ます in formal situations, e.g., 飲み (nomi-) + ます.

The non-past form can also express habitual actions or general truths. For example, 食べる (taberu) can mean “eat” or “will eat,” depending on context. This ambiguity is common in Japanese and usually clarified by additional words or context.

Past Tense Verb Formation

• Informal past tense verbs typically end with た (ta) or variations like った (tta), だ (da), depending on the verb.
• For example, the informal past of 飲む is 飲んだ (nonda, drank).
• Formal past tense adds ました (mashita) to the verb stem, e.g., 飲みました (nomimashita) for “drank” formally.

The informal past tense (the “た-form”) is crucial because it serves as a base for many other grammatical constructions. Understanding its formation and patterns is essential for progressing in Japanese.

Verb Group Differences

Japanese verbs are categorized mainly into three groups, and each forms present and past tenses differently:

Ru-Verbs (る verbs)

• Also called Ichidan verbs, these typically end with える or いる.
• To form the informal past tense, replace る (ru) with た (ta), e.g., 食べる (taberu) → 食べた (tabeta).
• Formal present and past tenses are made by attaching ます (masu) and ました (mashita) to the verb stem, which is the verb minus る (tabemasu, tabemashita).

U-Verbs (う verbs)

• Also called Godan verbs, they end with various “u” sounds (う、く、す、つ， etc.).
• Their informal past tense is formed by changing the final “u” syllable according to conjugation rules before adding た or だ.
• For example, 書く (kaku, to write) becomes 書いた (kaita) in the past.
• The formal forms are made by attaching ます / ました to the verb stem, which often involves a vowel change, e.g., 書きます (kakimasu), 書きました (kakimashita).

Irregular Verbs

• A handful of verbs do not follow standard patterns. The two most common are する (suru, to do) and 来る (kuru, to come).
• For example, する becomes した (shita) in the informal past and します (shimasu), しました (shimashita) in the formal forms.
• 来る becomes 来た (kita) in the informal past and 来ます (kimasu), 来ました (kimashita) formally.

Step-by-Step Guide for Forming Informal Past Tense for U-Verbs

1. Identify the verb’s final syllable.
2. Change the final syllable to its corresponding “i” sound to find the stem (if needed).
3. Apply the correct た/だ ending based on the final consonant:
   • Verbs ending in う (u), つ (tsu), る (ru) → replace with った (tta)
     • Example: 買う (kau) → 買った (katta)
   • Verbs ending in ぬ (nu), む (mu), ぶ (bu) → replace with んだ (nda)
     • Example: 飲む (nomu) → 飲んだ (nonda)
   • Verbs ending in く (ku) → replace with いた (ita), except 行く (iku) which becomes 行った (itta)
     • Example: 書く (kaku) → 書いた (kaita)
   • Verbs ending in ぐ (gu) → replace with いだ (ida)
     • Example: 泳ぐ (oyogu) → 泳いだ (oyoida)
   • Verbs ending in す (su) → replace with した (shita)
     • Example: 話す (hanasu) → 話した (hanashita)

Common Mistakes and Misconceptions

• Confusing informal and formal endings: It is common for beginners to mix た and ました or ます endings. た endings are informal and used mainly in casual speech and writing, while ました / ます are polite forms.
• Overgeneralizing Ru-verb patterns: Not all verbs ending in る are Ru-verbs; some are U-verbs and conjugate differently. For instance, 取る (toru, to take) is an U-verb despite ending with る.
• Using the non-past form for past events: Since the non-past can imply future, using it when past tense is required can confuse listeners.

Comparison with Other Languages

Unlike in many Indo-European languages, Japanese verbs do not inflect for person or number; the same verb forms are used regardless of whether the subject is “I,” “you,” or “they.” The emphasis is on politeness level and verb groups, simplifying verb conjugation in some respects while complicating it in others.

Summary Table of Verb Forms

Verb Type	Inf. Present	Formal Present	Inf. Past	Formal Past
U-verb	飲む (nomu)	飲みます (nomimasu)	飲んだ (nonda)	飲みました (nomimashita)
Ru-verb	食べる (taberu)	食べます (tabemasu)	食べた (tabeta)	食べました (tabemashita)
Irregular	する (suru)	します (shimasu)	した (shita)	しました (shimashita)

Useful Tips for Practice

• Memorize verb groups early to avoid confusion in conjugation.
• Practice common verbs first to build confidence.
• Listen to native speakers to get used to distinctions between informal and formal speech.
• Use the informal past tense as a foundation for learning more complex verb forms.

This expanded explanation covers essential points on how to form present and past tense verbs in Japanese, providing context, patterns, and nuance that support practical learning for polyglots.

References

• Japanese Tenses: Expressing the Past, Present, and Future

• Verb Plain Present る Form

• Japanese Past Tense: How to Use It Correctly + Examples

• The ULTIMATE Japanese Verb Conjugation CHEAT SHEET

• Japanese Verb Plain Past た Form

• Japanese Verbs: U-verbs, Ru-verbs and Conjugation

• Past Tense – Learn Japanese

• Making the Plain Past Form for Japanese verbs

• Japanese conjugation

• Master Japanese Verb Conjugation in One Article