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Since vs. For: What's the Difference?

Edited by Janet White || By Harlon Moss || Published on November 26, 2023
"Since" refers to the starting point of an action or event, while "for" denotes the duration of that action or event.

Key Differences

"Since" and "for" are two prepositions frequently employed to convey time in the English language, though they have distinct uses. Understanding when to utilize each one is pivotal in ensuring clarity and precision in one's statements.
"Since" is typically used to indicate a specific point in time when an event commenced. In essence, it refers to the starting time of an action or situation and is often paired with a precise time or date. For instance, saying "I have lived here since 2010" denotes that 2010 is the year the speaker began living in that location, and they've continued to do so until the present moment.
Conversely, "for" is employed to articulate the duration or span of an action or situation. It emphasizes the length of time that something has been happening. For instance, in the sentence "I have lived here for 10 years," the emphasis is on the decade-long duration of the speaker's residency.
Interestingly, while both "since" and "for" can be used in contexts describing actions that began in the past and continue into the present, their focal points differ. "Since" hones in on the onset of the action, whereas "for" emphasizes its continuous nature over a specific length of time. Recognizing this distinction ensures clarity in communication.
Both words, while central to expressing time, require different accompanying information. With "since," a specific point in time follows, while "for" is succeeded by a time duration. Ensuring the correct pairing is vital for accurate and comprehensible statements.

Comparison Chart

Use in Time

Starting point

Typical Follow-up

Specific date or time
Length of time


"I've known him since 2000."
"I've known him for 20 years."


Refers to the start of an action/event
Emphasizes how long an action/event has occurred

In Present Perfect

Used with a specific past time
Used with a duration

Since and For Definitions


Indicating the time something began.
It's been raining since morning.


In favor of; supporting.
Are you for or against the proposal?


After a time in the past.
I've felt better since taking the medicine.


Intended to be given to or used by.
This gift is for you.


From a particular past time until now.
I haven't seen him since Tuesday.


Indicating the duration of an event or action.
We've been waiting for an hour.


Continuously from a specific past time.
She's lived here since 2015.


Indicating purpose or reason.
She went to the store for some milk.


Because, given that.
Since you're here, help me move this.


Indicating destination or recipient.
He left for New York.


From then until now or between then and now
They left town and haven't been here since.


Used to indicate the object, aim, or purpose of an action or activity
Trained for the ministry.
Put the house up for sale.
Plans to run for senator.


Before now; ago
A name long since forgotten.


Used to indicate a destination
Headed off for town.


Can "since" and "for" be used interchangeably?

No, "since" refers to the starting point, while "for" refers to duration.

What follows "since" in time-related contexts?

A specific date or time, like "since 2015" or "since noon."

Is "since" ever used in causal contexts?

Yes, it can mean "because," e.g., "Since it rained, we stayed in."

How do you describe an ongoing action with "for"?

Use it with a duration, like "for three hours."

Which tense often accompanies "for" and "since"?

The present perfect, e.g., "I have lived here since 2010."

Can "for" be used outside of time contexts?

Yes, e.g., "This is for you."

Can "for" denote support?

Yes, e.g., "I'm for the new policy."

How is "since" different from "from"?

"Since" indicates the start of a continuous action, while "from" often requires an endpoint.

Can "since" begin a sentence?

Yes, often in causal contexts, e.g., "Since it's late, let's go."

How do I choose between "for" and "since"?

Determine if you're specifying a start point ("since") or duration ("for").

Can "since" indicate a future time?

Rarely. It usually references past times extending to the present.

Do "since" and "for" only relate to time?

No, both have other functions, like causality for "since" and purpose for "for."

Can "since" be used in negative sentences?

Yes, e.g., "I haven't eaten since morning."

Can "for" indicate against something?

No, "for" typically indicates support or favor.

How is "since" used in questions?

E.g., "Since when have you known?"

How do I emphasize duration with "for"?

Use it with strong adverbs, e.g., "for quite a while."

Can "for" indicate purpose?

Yes, e.g., "She's studying for her exams."

Is "since" exclusive to time contexts?

No, it can also indicate causality.

Is "for" used with specific past dates?

No, "for" pairs with durations, not specific dates.

What if an event's duration is unknown?

Use "for" with approximations, like "for several hours."
About Author
Written by
Harlon Moss
Harlon is a seasoned quality moderator and accomplished content writer for Difference Wiki. An alumnus of the prestigious University of California, he earned his degree in Computer Science. Leveraging his academic background, Harlon brings a meticulous and informed perspective to his work, ensuring content accuracy and excellence.
Edited by
Janet White
Janet White has been an esteemed writer and blogger for Difference Wiki. Holding a Master's degree in Science and Medical Journalism from the prestigious Boston University, she has consistently demonstrated her expertise and passion for her field. When she's not immersed in her work, Janet relishes her time exercising, delving into a good book, and cherishing moments with friends and family.

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