Potential Form: Irregular Verbs (Suru and Kuru)

Potential Form: Irregular Verbs (Suru and Kuru) is a high-value Japanese grammar point in the Potential Form area. This guide is designed for practical control, not passive recognition. The goal is simple: choose the pattern quickly, place it correctly, and keep your sentence natural in real communication. Learners usually understand the rule at reading level first, then lose accuracy while speaking under pressure. This page closes that gap by giving you a stable decision process and repeatable sentence frames.

Core Meaning and Function

At a functional level, this grammar point helps you encode one or more of these dimensions: relationship between ideas, speaker stance, sentence framing, or discourse flow. You will get better results by asking three questions before speaking: What meaning do I need? Where does this form attach? What register fits this context? Key forms to watch: Irregular Verbs Suru, Kuru. When these forms are used well, your sentence sounds intentional and fluent. When they are misplaced, the message may still be understood, but rhythm and precision drop.

Structure and Placement Checklist

Use this checklist every time:

1. 1Identify the message role first (statement, contrast, cause, condition, emphasis, question, or softening).
2. 2Insert the target form at the structural position where native speakers expect it.
3. 3Verify agreement, polarity (positive/negative), and word order around the target form.
4. 4Read the full line aloud once and adjust rhythm for clarity.

Pattern frame you can reuse: [Context] + [Target Form] + [Main Message]. Then practice variants: affirmative, negative, and question forms that keep the same core meaning.

Natural Rhythm and Register

Accuracy is not enough; delivery matters. In casual conversation, shorter clauses and high-frequency combinations usually sound more native. In neutral writing, keep links explicit and avoid overloaded sentences. In formal contexts, maintain precision and avoid slangy shortcuts unless the genre allows them. If a sentence feels heavy, split it into two clauses and keep only one key meaning per clause. This improves both comprehension and confidence.

Common Mistakes and Fast Fixes

1. 1Literal translation from English word order. Fix: start from a native-like frame, then fill content.
2. 2Correct form, wrong position. Fix: mark the anchor point in the sentence before writing.
3. 3Register mismatch. Fix: decide formal, neutral, or casual before choosing vocabulary.
4. 4Unstable negatives/questions. Fix: practice one base sentence and transform it systematically.