～やすい・～にくい

How it works

Take the ます-stem of a verb (the form ます attaches to) and add やすい ‘easy to …’ or にくい ‘hard to …’. The result is an ordinary い-adjective and conjugates like one: 読みやすい, 読みやすかった, 読みやすくない, 読みやすくて, 読みやすく. It is the same stem that ～たい, ～ながら and ～すぎる use.

• 飲む → 飲みやすい ‘easy to drink’, 飲みにくい ‘hard to swallow’
• 分かる → 分かりやすい ‘clear’, 分かりにくい ‘confusing’
• 使う → 使いやすい ‘user-friendly’, 使いにくい ‘awkward to use’
• 食べる → 食べやすい, 食べにくい
• する → しやすい, しにくい; 来る → 来（き）やすい, 来（き）にくい

Each suffix carries two related meanings:

1. Ease or difficulty for the doer: この本は読みやすい ‘this book is easy to read’, この道は歩きにくい ‘this path is hard to walk on’, 田中さんは話しやすい ‘Tanaka is easy to talk to’.
2. Tendency: the thing does it readily, or resists doing it. 割れやすい ‘breaks easily, fragile’, 風邪をひきやすい ‘catches colds easily’, 汚れにくい ‘does not get dirty easily’, 忘れにくい ‘hard to forget, memorable’.

When the sentence is about the thing (this book, this kanji), that thing is the topic or subject and takes は or が, not を: 漢字が読みにくい. When the subject is a person, the verb's own object keeps its を: 私は風邪をひきやすい. Before another verb use the adverbial く-form: 分かりやすく説明してください ‘please explain it clearly’, 食べやすく切る ‘cut into bite-size pieces’.

Examples

• この本は字が大きくて読みやすいです。（この ほん は じ が おおきくて よみやすい です）— This book has big print and is easy to read.
• 先生の説明は分かりやすかったです。（せんせい の せつめい は わかりやすかった です）— The teacher's explanation was easy to understand.
• このガラスは割れやすいから、気をつけてください。（この ガラス は われやすい から き を つけて ください）— This glass breaks easily, so be careful.
• 新しい靴は歩きにくいです。（あたらしい くつ は あるきにくい です）— The new shoes are hard to walk in.
• 冬は風邪をひきやすいです。（ふゆ は かぜ を ひきやすい です）— In winter you catch colds easily.
• もう少し分かりやすく説明してください。（もう すこし わかりやすく せつめい して ください）— Please explain it a little more clearly.

Compare with

Potential form (読める・読めない)

読めない says the reader lacks the ability or the conditions (no glasses, too dark). 読みにくい says the text itself resists: tiny print, bad handwriting. A native speaker finds a scrawled note 読みにくい but can still 読める.

～すぎる

Same stem, different suffix: 食べすぎる ‘eat too much’ is a verb, 食べやすい ‘easy to eat’ is an adjective. 飲みやすいお酒はつい飲みすぎてしまう ‘drinks that go down easily get overdrunk before you notice’ puts both in one sentence.

～づらい

言いづらい, 見づらい, 歩きづらい: like にくい but stressing the speaker's own discomfort, so it suits actions a person does. A jacket is 汚れにくい, never 汚れづらい.

Traps for Spanish, English and French speakers

• Spanish ‘fácil de leer’ and French ‘facile à lire’ keep the infinitive, so learners attach the suffix to the dictionary form: 読むやすい, 食べるにくい. The suffix goes on the ます-stem, the same one as ～たい: 読みやすい, 食べにくい, しやすい, 来（き）にくい.
• English ‘I can't read this’ and Spanish ‘no puedo leer esto’ about a scrawled note lead learners to この字は読めません, which sounds like an admission that they cannot read. When the fault is in the handwriting or the print, blame the object: この字は読みにくいです.
• Spanish speakers translate ‘difícil’ straight onto the verb: この漢字は書く難しいです. Either nominalise (書くのが難しい) or, for a specific thing that resists the pen, use the suffix: この漢字は書きにくいです.
• やすい sounds exactly like 安い ‘cheap’, and learners who met 安い first read 使いやすい as ‘cheap to use’ or write 使い安い. The suffix is 易い ‘easy’, always written in kana after a verb stem, and has nothing to do with price.