"By" vs. "Until"

Understanding the prepositions "by" and "until" in English is essential for clear communication, especially when discussing time. Both prepositions are related to time, but they have distinct uses. Today, we’re going to take a closer look at these prepositions to help you use them correctly and confidently.

"By"

The preposition "by" plays a crucial role in expressing deadlines in the English language. It sets a clear endpoint or limit by which a particular action or task must be completed. Here are some examples:

"Be home by 10 PM."

"Finish the project by Monday."

"Submit your application by the end of the week."

"I'll have the report ready by your morning coffee."

The essence of "by" is that it specifies a latest possible time, ensuring that the action takes place either before or at that moment, but not after. The preposition "by" is often employed in scenarios where timing is of the essence and there is a need to convey a sense of urgency or a definitive time constraint.

"Complete your exercise by 7 AM."

"Return the books by next Friday."

"Have the room cleaned by noon."

Using "by" sets a specific endpoint or deadline for an action.

"Until"

In contrast, "until" describes the continuation of an action up to a certain point in time. It signifies that the action is ongoing and will cease at the specified time. Here are examples of its usage:

"Stay here until I return."

"The store is open until 9 PM."

"Keep the oven on until the cake is baked."

"Until" is used when you're talking about something that keeps going on and doesn't stop until a specific time or event happens. It's like saying, "Keep doing this until that time or moment."

For example, if I say, "Keep the shop open until 8 PM," it means the shop should continue to operate and then close at 8 PM. Here are some more example sentences:

"She read books until she fell asleep."

"Work on the puzzle until it's finished."

"The event will continue until midnight."

"Keep the documents until they are no longer needed."

With "until," the emphasis is on the continuity or duration of an action up to a particular moment.

To wrap up, grasping the correct application of "by" and "until" is key to accurately conveying time-related information in English. Whether you're specifying a deadline or describing the duration of an activity, these prepositions are fundamental in expressing time-related concepts.

For a more interactive learning experience, explore our "Daily Dose of Denglisch Docs" series, which includes segments on prepositions like "by" and "until," and lots of other interesting topics.