Difference between だろう and かな


What is the Difference between だろう and かな and how to use them




It is not hard to understand exactly what both expressions mean by analyzing
where they are coming from.

**だろう**

  1. だろう comes from だ
  2. だろう is だろ (the 未然 conjugation of だ) + う (助動詞 for 推量 in this case)

The 助動詞 う is not often used for 推量 in everyday speech apart from when it is
used with だ (だろう) (or in fixed expressions). Using it may result in you
sounding poetic, classical or old school:

> 馬はさぞ寒かろう。

This sentence could be written as below in everyday Japanese:

> 馬はきっと寒いだろう。

Anyway, I like to see だろう as "must" as in " _he must be hungry_ ". It always
works and is I think the best way to interpret it (but not always the best
translation). It indicates a strong guess/presumption/supposition.

When using it, you kind of "push" your opinion/guess to others, without
necessarily expecting a reaction. (that depends on the intonation)

**かな**

か is what most people would call the "question particle" (it expresses
uncertainty). And if we look up な in a dictionary, we get:

> 相手の返答・同意を求めたり、念を押したりする意を表す。

Which basically means "Expresses the intention to get the other's
consent/reaction, or to remind someone of something".

The two particles combined together indicate that you want to get other's
reaction on the question. So it means that you wonder about something, and you
want other's opinion about it.

It's translated as " _I wonder if..._ " most of the time.

