A couple of months ago, a friend asked me about the difference between 使用 (shiyō, use) and 利用 (riyō, use), and for a moment I was stumped.

I knew that they were both related to 使う (tsukau), meaning “to use,” and I’m sure I could have understood and explained example sentences had she provided them, but I only had a vague sense of how to articulate the difference in the form of a definition. Clearly my active ability to use these two words was somewhat limited.

I could have reacted to this situation in a couple different ways.

I could have overreacted: This was a failure on my part — I hadn’t studied enough, or I wasn’t smart enough to understand and retain the difference between these words.

Or I could have taken it much less seriously: This was a common situation that people face — even in English I don’t always know the exact definition of words. I often read through with a loose understanding based on context. I look up the definitions of words to confirm or clarify my understanding. There’s no reason I couldn’t do this in Japanese.

Not beating yourself up over small errors is an important habit to develop when learning a foreign language. Another good habit for Japanese language learners is to look up definitions in Japanese, especially as you progress from intermediate to advanced levels of study.

In this case, I could have (and probably should have) gone to the reliable online dictionary Kotobank.jp, which has a beautiful interface and provides simple, clear definitions.

But I was curious to see if the Japanese were having the same issue, so I looked it up online. Judging by the volume of websites addressing this specific word pair, it’s a very common question to ask.

I found the website Chigai-allguide.com, which provided easy to understand definitions with some nice contextual examples (bit.ly/ShiyoRiyo) 使用 means 人・物・システム・場所などを使うこと (hito/mono/shisutemu/basho nado o tsukau koto, using something, like a person, thing, system or place), while 利用 means 物・システム・施設・設備などの持つ機能や特性を活かし、役に立つよう用いること (mono/shisutemu/shisetsu/setsubi nado no motsu kinō ya tokusei o ikashi, yaku ni tatsu yō mochiiru koto, using a thing, facility or equipment’s unique function so that it’s helpful).

Simplified, 使用 is “use” while 利用 is closer to “make use of.” You can use both of these words with クーポン (kūpon, coupon), and the former would simply be “use a coupon” while the latter would emphasize using the coupon’s ability to save you money.

Plenty of other websites had interesting explanations. The Mainichi Shimbun has a series titled コトバ解説 (Kotoba Kaisetsu, Word Explanation) (bit.ly/KotobaKaisetsu) that uses manga to explain the difference of everything from 終了 (shūryō, end) and 完了 (kanryō, complete/conclude) to ビーフシチュー (bīfu shichū, beef stew) and ハッシュドビーフ (hasshudo bīfu, hashed beef).

Kotoba Kaisetu explains 使用 by showing a cartoon 電話帳 (denwachō, telephone book) being used to compress a bucket of 漬物 (tsukemono, pickled vegetables) — this is 特定の目的のために使うこと (tokutei no mokuteki no tame ni tsukau koto, using something for a specific purpose).

With 利用, on the other hand, a person is using the 電話帳 to find the number for a 水道修理 (suidō shūri, plumber) — which is to say, 本来の特徴や機能を生かして使うこと (honrai no tokuchō ya kinō o ikashite tsukau koto, making use of something’s innate characteristics or functions).

The subtle differences between the definitions on these two sites helps us triangulate a meaning in Japanese.

There are tons of sites worth exploring, so I invite you to Google a pair of words yourself. Just line them up and add 違い (chigai, difference) on the end. In all likelihood, you’ll probably see the same search in Google’s autocomplete, suggesting it gets a lot of hits.

I had fun exploring Chigai-allguide.com, looking at the differences between ゆっくり (yukkuri, slowly) and のんびり (nonbiri, easygoing) (bit.ly/Yukkuri)

The post for the homonyms 悲しい (kanashii, sad) and 哀しい (kanashii, sad) is also interesting (bit.ly/Kanashi) There’s very little difference between the meaning, and both are included as 常用漢字 (jōyō kanji, common-use kanji), but because only 悲 is listed with the pronunciation かなしい (kanashii), 哀 cannot be used to write the word かなしい in official government documents, which is … a little sad.

There are other good sources for Japanese explanations and definitions other than the internet, of course, and one of the best is Kurosio Publishers’ 日本語文型辞典 (“Nihongo Bunkei Jiten,” “A Handbook of Japanese Grammar Patterns for Teachers and Learners”). It has wonderful, detailed explanations of grammatical structures and usages and many example sentences for each entry. For example, there’s a great look at the difference between なくてはならない (nakute wa naranai, must/have to) and なくてはいけない (nakute wa ikenai, must/have to).

The former, the book explains, is a result of obligation or necessity out of 社会常識 (shakai jōshiki, common sense) — everyone would feel the same duty.

The latter, on the other hand, is a result of necessity from 個別の事情 (kobetsu no jijō, individual circumstances).

The book is a hefty tome, so I recommend reading as you must or picking a few entries each day to focus on. And I recommend tapping into as much 我慢 (gaman, patience/perseverance) as you can. Reading grammatical explanations isn’t a thrill, but keeping at it will absolutely build your understanding of the language in the long run.