Presuming or supposing something, with no particular information or evidence to back up that position, is expressed by appending だろう (from だ) or でしょう (from です) to a noun, verb, or adjective. As an expression, it has the meaning of “I wonder” or “don’t you agree?”

Examples of 〜だろう and examples of 〜でしょう

See Also

• Might with かもしれない

Further Reading

• Kamiya, Taeko. “Expressing Conjecture and Hearsay, and Quoting People.” Japanese Sentence Patterns for Effective Communication, Kodansha, 2005, p. 217
• Makino, Seiichi and Michio Tsutsui. “Main Entries.” A Dictionary of Basic Japanese Grammar, The Japan Times Ltd., 1989, pp. 100–102