Concept:
In English grammar, the prepositions
“since” and
“for” are commonly used with the
present perfect tense or
present perfect continuous tense to describe actions that started in the past and continue in the present.
The difference between them is:
- Since is used with a specific point in time.
- For is used with a period or duration of time.
Examples:
- Since 2010
- Since Monday
- Since morning
- For five years
- For two months
Step 1: Analyze the sentence.
\[
\text{"He has been living in this city _______ 2010."}
\]
The year
2010 represents a
specific point in time.
Step 2: Choose the correct preposition.
Since we are referring to a specific starting point in the past, the correct preposition is:
\[
since
\]
Step 3: Check the other options.
- Option (A): since — Correct; used with a specific time point.
- Option (B): for — Used with durations (e.g., for ten years).
- Option (C): from — Usually used with "to" or "till".
- Option (D): by — Indicates deadline or limit, not duration.
Step 4: Correct sentence.
\[
\text{"He has been living in this city
since 2010."}
\]
Final answer:
\[
\boxed{\text{since}}
\]