だいたい

だいたい is an adverb with several related meanings, all revolving around the idea of "approximate completeness." It can express approximation, generality, or that something is mostly the case. It is used in both casual and polite speech.

Approximately / Roughly

When used with numbers, quantities, or time expressions, だいたい means "approximately" or "about." It indicates that the figure given is not exact but close enough.

Mostly / For the most part

だいたい can describe that something is mostly done or largely true, implying near-completeness but not 100%.

Generally / Usually

だいたい can also mean "generally" or "usually", describing what typically happens or is the case.

When used with time expressions describing routine, だいたい carries both the "usually" and "approximately" nuances simultaneously – it means "usually around that time."

Comparison with similar words

• ほとんど means "almost all" and implies a higher degree of completeness than だいたい.
• たいてい is closer to "usually" and is primarily used for habitual actions, whereas だいたい has the additional meaning of "approximately."
• やく約 (やく) is a more formal way to say "approximately" and is typically placed directly before a number (約10分), while だいたい is more conversational and flexible in placement.