
Hitherto
Past Reference
Use 'hitherto' to refer to a period extending into the past, up to the current point or event discussed.
His hitherto spotless reputation was now under scrutiny.
Formal Tone
'Hitherto' often appears in formal or academic texts rather than casual conversation.
The hitherto accepted theories are now being questioned.
Emphasis on Change
Use 'hitherto' when emphasizing a change from past to present, particularly when introducing newly discovered information.
This hitherto unexplored area offers great scientific potential.