副詞「however」は、日本人に最もよく誤用される語の一つです。その誤用は何種類かに分けられますが、ここでは文法上の誤りを考察します。

「however」には主な意味が二つあり、それぞれ、「but」そして「in whatever way」と同義です。前者の場合には「 however 」は必ず副詞ですが、以下が示すように誤って接続詞として使用されていることをしばしば目にします。

• [誤] I would like to go to a movie, however I have no money.
• [正] I would like to go to a movie, but I have no money.
• [正] I would like to go to a movie. However, I have no money.

• [誤] The argument given in Ref. [3] may be correct, however it is not convincing.
• [正] The argument given in Ref. [3] may be correct, but it is not convincing.
• [正] The argument given in Ref. [3] may be correct. However, it is not convincing.
• [正] Although/While/ the argument given in Ref. [3] may be correct, it is not convincing.

上記の訂正例では、「but」、「although」、「while」はいずれも正しく接続詞として機能しており、「However」は副詞となっています。

詳しくはグレン・パケット：『科学論文の英語用法百科〈第1編〉よく誤用される単語と表現』（京都大学学術出版会，2004）の第65章をご参照下さい。

出典元：エナゴ学術英語アカデミー

化学論文での「however」の利用例

Compared to other hydrofunctionalization methods, however, transition metal-catalyzed hydrothiolation is relatively underexplored, likely due to sulfur’s strong coordinating ability and ensuing catalyst deactivation.
引用: 10.1021/jacs.6b07142

Over 160 chiral vicinal bromochlorinated natural products have been identified; however, a lack of synthetic methods for the selective incorporation of halogens into organic molecules has hindered their synthesis.　引用：10.1021/jacs.5b08398

There was good agreement between our observations and computational predictions. No reaction or low yields were seen for substrates 7a–7e (entries 1–5). However, when the calculated DG and the oxidative addition barrier were favourable, substantial formation of product 8a was observed (entries 6 and 7) 引用：10.1038/nature14615