The Classical Negative (〜ず)

ず is the classical version of the negative ending ない. It is often used in formal writing, idioms, and other advanced grammatical structures. For Group 1 and 2 verbs, we simply replace ない with ず as per the following table:

English	Dictionary	Negative	ず Form
to go	行いく	行いかない	行いかず
to swim	泳およぐ	泳およがない	泳およがず
to go home	帰かえる	帰かえらない	帰かえらず
to say	言いう	言いわない	言いわず
to think	考かんがえる	考かんがえない	考かんがえず

Group 3 verbs are irregular, as shown below:

English	Dictionary	Negative	ず Form
to do	する	しない	せず
to come	来くる	来こない	来こず

Without doing (〜ずに)

To use this grammar point to mean “without doing [verb]” (the formal equivalent of 〜ないで), we simply append the particle に to form 〜ずに.

あまり相手あいての気持きもちを考慮こうりょせずに厳きびしい言葉ことばを投なげ掛かけた。

Without really considering the other person’s feelings, he hurled some harsh words.

考かんがえずに旅行りょこうの予約よやくを入いれる。

To book a holiday without thinking.

予約よやくせずにお店みせへ行いく。

To go to a restaurant without making a reservation.