さぞ

JLPT Level: N1
Meanings

You must be very ~

How … you must be

I dare to say you’re surely ~

I am sure (that) you must be very ~

Usage

さぞ + お忙しいでしょう

さぞ + お困りのことでしょう

さぞ + お美しいですね

さぞ + おいしいでしょう

Explanation
さぞ is used to express strong conjecture or empathy about someone’s situation, based on what you know or have heard. It conveys that you are certain, or at least strongly believe, that the listener is experiencing something to a noticeable degree. It carries a tone of respect and consideration, often when making polite compliments, condolences, or assumptions about another person’s feelings or state. It is more formal and assertive than simple だろう/でしょう statements and is commonly heard in writing, media, or polite conversation.
さぞお疲れのことでしょう。
さぞおつかれのことでしょう。

You must be tired, I’m sure.

さぞお忙しいことでしょう、今日は大変ですね。
さぞ おいそがしい ことでしょう、きょうは たいへん ですね。

You’re probably very忙しい today—this must be tough for you.

さぞ美しい景色だったろう。
さぞうつくしいけしきだったろう。

The scenery must have been beautiful, I bet.

さぞお困りのことと存じます。
さぞおこまりのこととぞんじます。

I assume you’re surely having trouble.