Should have brought an umbrella with 〜べきだった

お母(かあ)さん:

「傘(かさ)持(も)つべきだったねー。」

“We should have brought an umbrella, huh?”

お父(とう)さん:

「そうだなー。」

“You're right.”

Key Points

1. 〜べきだった = should have

   • This is べきだ in the past, so it expresses regret about what would have been the better choice earlier.

   • Here it means they should have brought an umbrella before leaving.

2. 傘(かさ)持(も)つべきだった

   • The base verb is 傘(かさ)を持(も)つ, “to carry an umbrella”.

   • The object marker を’s omission is a casual spoken shortening.

3. Scene nuance: reflection after the mistake is already obvious

   • Because it has already started raining, this is not advice for the future moment.

   • It is a hindsight comment: “We really should have brought one.”