Using Correct Prepositions for Deadlines

Using the correct prepositions for deadlines is essential for professional English writing and speaking. This video explains the difference between by, at, and on when referring to due dates and times.

“By” is used for a deadline, meaning no later than a certain day. For example: “The report is due by Friday.”
“At” is used for a specific time: “Submit your slides at 9 AM.”
“On” is used for a specific day or date: “The report is due on Friday.”

Using the wrong preposition can cause confusion in professional communication. For instance, saying “Submit your slides by 9 AM” clearly indicates the latest time they are expected, while “at 9 AM” pinpoints the exact moment.

Watch this video and practice filling in blanks with the correct preposition. Repeat the examples aloud and try writing your own sentences to reinforce your understanding. By mastering by, at, and on, you’ll write clearer emails, schedule tasks accurately, and sound confident in English.