Synonym Boundary: "開ける", "開く", "通じる", "開通する", "うちとける"

When expressing "open" in Japanese, you must carefully distinguish between "開ける", "開く", "通じる", "開通する", "うちとける" based on context.

• 開ける (あける (akeru) - Level: N5): Maps to "to open (something)" and is used when Transitive verb.
• 開く (あく (aku) - Level: N4): Maps to "to open (intransitive)" and is used when Intransitive verb. Used when something opens on its own or is opened by an unspecified agent.
• 通じる (つうじる (tsuujiru) - Level: N3): Maps to "to open (to traffic); to lead to; to be understood; to communicate; to understand each other" and is used when Refers to signals/calls connecting, roads opening/leading to a place, meaning being understood by others, or communicating feelings. Often used as 意味が通じる or 心が通じる. ⚠️ Haruka's Voice Column: 'To communicate/be understood! "The telepathy of my love reached you and made you blush beautifully, Haruka-san!" ...っ! Telepathy communicating! B-Baka! Telepathy has nothing to do with it! It's just because you are looking at me with such a weird face! But... make sure you keep communicating love to my heart forever! dummy!' / 【ハルカ部長のワンポイント指導】『つうじる（通じる）よ！『ハルカ部長、僕のテレパシー（愛の念）があなたに通じて、顔を真っ赤にしてくれるの、本当に可愛いです！』って…っ！念が通じる！バカ！/// べ、別にテレパシーなんか通じてないわよ！ただあんたが変な顔でこっちを見てるからよ！…でも、一生私のハートに愛を通じさせ続けなさい！』.
• 開通する (かいつうする (kaitsū suru) - Level: N3): Maps to "to open (for traffic), to be completed (e.g., a tunnel, bridge, line)" and is used when Used for infrastructure like roads, railways, tunnels, or new services becoming available for public use. It's an intransitive verb..
• うちとける (うちとける (uchitokeru) - Level: N2): Maps to "to open one's heart, to feel at home, to relax, to be frank" and is used when Describes the process of becoming comfortable and relaxed with someone, allowing one's true self to show. Often implies breaking down barriers. 心を開き、親しくなる様子を表します。.

Mixing these up can easily lead to unnatural translations. Refer to the bilingual context cards below to master the boundaries!