What it means
ことだし gives a reason for a decision, suggestion, or conclusion, often with the implication that it is one reason among several. It commonly presents a circumstance as a natural basis for what follows, with a nuance similar to “since” or “given that.” The clause before it normally uses a plain form. With a noun, のことだし is used; with a na-adjective, なことだし is used. The polite counterpart is ことですし, while the clause before it can remain in plain form.
Usage note
ことだし often sounds more deliberate and explanatory than a simple から. It is frequently used when proposing an action or drawing a conclusion from a relevant circumstance. Do not confuse it with ことだ, which can express advice or obligation, or with sentence-final し, which can list reasons without the ことだし construction.
How to use it
彼女のことですし、慎重に確認するでしょう。
Knowing her, she will check carefully.
この会場は駅に近くて便利なことですし、ここに決めましょう。
Since this venue is conveniently close to the station, let us decide on this place.
費用も安いことですし、この案を採用しましょう。
Since the cost is low, let us adopt this plan.
資料もそろったことですし、会議を始めましょう。
Since the materials are ready, let us start the meeting.
彼女のことだし、慎重に確認するだろう。
Knowing her, she will check carefully.
この会場は駅に近くて便利なことだし、ここに決めよう。
Since this venue is conveniently close to the station, let us decide on this place.
費用も安いことだし、この案を採用しよう。
Since the cost is low, let us adopt this plan.
資料もそろったことだし、会議を始めよう。
Since the materials are ready, let us start the meeting.
Example sentences
天気も穏やかなことだし、今日は庭の手入れをしよう。
Since the weather is also mild, let's tend to the garden today.
資料もそろったことだし、明日の会議で新しい計画を提案しよう。
Since the materials are all ready, let us propose a new plan at tomorrow's meeting.
駅からも近いことだし、祖母の退院祝