〜だろう

§ What does 〜だろう mean?

The Japanese auxiliary verb 〜だろう (darō) is a very useful phrase for expressing probability or conjecture. At its core, it means 'probably,' 'I think,' or 'it is likely.' You'll hear and use it constantly in everyday Japanese conversations. It's a key component for sharing your thoughts about future events or current situations where you don't have 100% certainty.

§ When do people use 〜だろう?

People use 〜だろう when they want to express:

• Conjecture or probability: This is the main use. You're saying something is probably true, but you're not stating it as a fact. For example, if you look outside and see dark clouds, you might say it's probably going to rain.
• Asking for confirmation (with rising intonation): While less common than direct questions, adding 〜だろう with a rising tone can sometimes be used to ask for agreement or confirmation, similar to 'right?' or 'isn't it?' in English. However, be careful as this can sometimes sound a bit assertive or rhetorical depending on the context.
• Softening a statement: Adding 〜だろう can make a statement sound less direct and more like a personal opinion or a gentle suggestion. This can be useful in maintaining politeness, especially when disagreeing or offering advice.

It's important to remember that 〜だろう is the plain form. The polite form is 〜でしょう (deshō). While they mean the same thing, the choice between 〜だろう and 〜でしょう depends on who you are talking to and the formality of the situation. For beginners, focus on understanding the core meaning first, and then practice switching between plain and polite forms.

§ Basic Connections for 〜だろう

〜だろう connects differently depending on the word type it follows:

Nouns

Noun + 〜だろう

な-adjectives

な-adjective stem + だ + 〜だろう (or sometimes just the stem + 〜だろう, especially in casual speech)

い-adjectives

い-adjective + 〜だろう

Verbs

Plain form of verb (present or past) + 〜だろう

§ Similar words and when to use this one vs alternatives

When you want to express probability or conjecture in Japanese, you have a few options. Let's look at how ～だろう (darō) compares to some other common expressions like ～でしょう (deshō), ～かもしれません (kamoshirenai), and ～と思います (to omoimasu).

DEFINITION

～だろう (darō) expresses a high degree of probability or a strong conjecture, often based on some evidence or a personal feeling. It's more direct and less polite than ～でしょう (deshō).

This sentence uses ～だろう because the speaker has a strong feeling or some information that makes them think it's likely to rain.

§ ～でしょう (deshō) vs. ～だろう (darō)

The main difference between ～だろう and ～でしょう is politeness and formality. ～でしょう is the polite form of ～だろう.

DEFINITION

～でしょう (deshō) also expresses probability or conjecture, but it's used in more polite or formal situations, or when you want to soften your statement. It can also be used to seek agreement.

§ ～かもしれません (kamoshirenai) vs. ～だろう (darō)

When the probability is lower, or you want to express more uncertainty, ～かもしれません is a good choice.

DEFINITION

～かもしれません (kamoshirenai) means 'might' or 'may,' indicating a possibility rather than a strong probability.

Compare this to the previous example with ～だろう. With ～かもしれません, the speaker is less certain about the rain. It's more like a 50/50 chance, whereas with ～だろう, the probability feels higher.

§ ～と思います (to omoimasu) vs. ～だろう (darō)

While both express an opinion or thought, ～と思います is more about your personal belief, while ～だろう is about your estimation of a situation.

DEFINITION

～と思います (to omoimasu) means 'I think that...' and expresses your personal opinion or belief. It's a statement of your internal thought process.

Here, the speaker is stating their belief about the weather. They might have no particular evidence, it's just what they think. In contrast, with ～だろう, there's usually some implicit or explicit reason for the conjecture.

• When you are quite confident about something and speaking informally, use ～だろう.
• When you are confident but need to be polite, use ～でしょう.
• When you are less certain and want to express a possibility, use ～かもしれません.
• When you are stating your personal opinion or belief, use ～と思います.

By understanding these subtle differences, you can choose the most appropriate expression for your Japanese conversations and writing. Practice using them in different contexts to get a feel for their nuances.