Find the Dictionary Word Behind a Japanese Verb Form

To recognize a conjugated Japanese verb, keep the encountered form and look for a checked correspondence with its dictionary form. Conjugation is a change in a word's form for a grammatical use. Removing a familiar ending can help you notice the structure, but it does not always recover a complete dictionary word.

This guide works through one verb rather than supplying another full conjugation chart. The TUFS three-group table gives the form correspondences, and its polite-verb explanation establishes the relevant polite forms and uses.

Keep the encountered form

Suppose you meet 読みます (よみます, yomimasu, "read," in its polite nonpast form). The TUFS vocabulary entry gives its reading and English meaning. Nonpast means the form is not marked as past; the sentence's context helps determine whether it describes a habit, a state or a future plan.

You recognize the polite ending. If you simply delete its masu sounds, however, you are left with yomi. That is not the dictionary form shown in the checked table. Deleting an ending has identified a piece of the form, not finished the lookup.

The table connects the encountered form with 読む (よむ, yomu, "read," the dictionary form). A dictionary form is the basic form used to identify the verb in a dictionary or grammar table.

Verify the correspondence

For this verb, the sound before the polite ending differs from the end of the dictionary form. Follow the table's correspondence from yomimasu to yomu rather than searching for a rule that only removes letters.

The group also matters. TUFS separates verbs into three groups with different patterns. Do not infer that every word ending in the same sound belongs to the same group, or that a correspondence confirmed for this verb applies unchanged to all others.

The masu-form guide covers the forward formation task. Use it when you need to learn the pattern itself. The task here runs in the other direction: what checked entry could explain the form you encountered?

Recognize a second shape

The same TUFS table connects the reading verb with 読んで (よんで, yonde, "read," in the connective te form). A connective form helps a verb join another grammatical element; this isolated form is not a complete statement with one fixed English tense.

Here the visible change is larger than a polite ending added to an unchanged dictionary word. Keep the complete encountered form and consult the relevant correspondence. Cutting off the final sound does not automatically reconstruct the dictionary form.

This second case also shows why a lookup candidate needs checking. A familiar ending is evidence about possible grammar. It is not, by itself, proof of the word's spelling, meaning or intended use in the sentence.

Return to the original sentence

1. Copy the complete form you encountered, with its surrounding sentence.
2. Identify a familiar ending or changed shape.
3. Use a reliable entry or group table to propose a dictionary form.
4. Check that entry's reading and meaning.
5. Return to the original sentence and confirm that the meaning and grammatical use fit.

If the candidate does not fit, keep looking. An adjective, an unfamiliar verb group or a long chain of attached forms may need a different explanation. This short routine is not an automatic way to recover every Japanese word.

The vocabulary guide covers keeping words with examples. Choose a familiar verb through the public library's verb topic, then record one checked encountered form beside its dictionary form in your own notes. Keep the original sentence so the lookup remains connected to meaning.

Sources

• TUFS: three verb groups and checked form correspondences — The table explicitly pairs the reading verb's dictionary, polite, negative, past and connective forms in romaji, and distinguishes three groups. Supports recovering a candidate by a checked correspondence, not a universal suffix-deletion algorithm. (checked 2026-10-17)
• TUFS: polite nonpast verb forms — Explains polite positive/negative nonpast forms and their habit, state and future-plan uses. It does not make the ending a grammatical-person marker or make deletion recover every dictionary form. (checked 2026-10-17)
• TUFS: the reading verb's pronunciation and meaning — The original vocabulary entry pairs the polite reading verb with its kana reading and English gloss read, plus a book-reading example. No audio playback claimed. (checked 2026-10-17)

Prepared by our editorial team with AI assistance. Product details are checked against the sources below.

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