さぞYou must be very, How … you must be, I dare to say, I am sure or certain that you must be very

さぞ is a fairly formal adverb in Japanese that is used emphatically to highlight that the following statement is something that the speaker understands to be true. This is often in relation to the feelings or situation of another. Common translations include 'you must be very (A)', 'how (A) you must be', or 'I dare say that (A)'. 'I dare to say that (A)' is probably the closest to the literal meaning of さぞ, as the speaker is empathizing with someone else by trying to imagine the situation from their point of view.

As さぞ is an adverb, it will usually appear at the beginning of a sentence, modifying the whole phrase that follows.

The phrase following さぞ will often finish with だろう or でしょう. This highlights the speaker's opinion about the situation as being limited by their own knowledge.

Caution

さぞ comes from the kanji 嘸(さぞ), which has two alternative readings, 嘸(さぞ)や, and 嘸(さぞ)かし. Both 嘸(さぞ)や, and 嘸(さぞ)かし are occasionally used as even further emphasized versions of さぞ.

Despite being almost identical in meaning, さぞかし is used more often than さぞや.