Key Difference

• For is used to indicate a duration or length of time (e.g., how long something lasts).
• Since is used to refer to the starting point of an action or event that continues up to the present.

1. When to Use For

Use for when you want to express how long something has been happening. This word is all about the total time period—the length of time, not when it started. It works with both the past and the present tense.

Examples:

• “I’ve been studying English for two hours.” 🕐 (length of time)
• “They lived in Japan for five years.” (duration of time)
• “She has been working here for a decade.”

Pro Tip: Think of for as focusing on the quantity or duration of time!

Common Time Expressions with For

• for two minutes
• for three days
• for four weeks
• for several months
• for many years

1. When to Use Since

Use since to talk about when something started and continues up to now. This word is all about the starting point—it marks the moment something began, and it’s typically paired with the present perfect tense.

Examples:

• “I’ve been studying English since 2 o’clock.” 🕑 (starting point)
• “They have lived in Japan since 2018.”
• “She has been working here since last Monday.”

Pro Tip: Think of since as highlighting the beginning of a time period!

Common Time Expressions with Since

• since January
• since last year
• since I was a child
• since 10 a.m.
• since we met

Comparing For and Since in Context

Let’s look at some examples side by side to see how the choice between for and since changes the meaning:

• “I have been working here for three years.” (how long I’ve worked)
• “I have been working here since 2020.” (when I started working here)

Notice how:

• For answers “how long?”
• Since answers “since when?”

Practice Exercise

Try filling in the blanks with either for or since to see if you’ve got the hang of it!

1. “He has lived in this city ___ ten years.”
2. “They have been friends ___ childhood.”
3. “I haven’t seen her ___ last summer.”
4. “We’ve been waiting ___ over an hour.”

Answers:

1. for
2. since
3. since
4. for

Final Learning Tip 🎉

When deciding between for and since, ask yourself:

• “Am I talking about the total time spent?” If yes, use for.
• “Am I talking about the starting point?” If yes, use since.