by, near

In expressions of time, by means “not later than” or “at or before a specified time.”

• I want those essays by June 25. You will have until midnight of that day to turn them in.

In expressions of place, by means “near” or “passing through.”

• He left his car by the old house and continued on foot.
• The road between Toronto and Ottawa is longer if you go by Montréal.

In passive constructions, by can also refer to the author of an action or to the means used for an action.

• This book was not written by Margaret Atwood.
• During their year-long trip through South America, they travelled great distances by bus and by train as well as on foot.

Be careful: these varied uses occasionally produce unintentional humour or confusion.

• Ambiguous: The murder weapon was found by the dead man.
• Clear: The murder weapon was found near the dead man.