For vs Since: Difference between For and Since

There are a few key differences between the two sentence types. First, “since” is used to introduce a temporal clause, while “for” is used to introduce a spatial clause. Second, “since” always requires a conjunction (and, or, nor), while “for” can optionally use a conjunction (and, or, nor). Third, “since” always has an active voice (I am writing this), while “for” can have either an active or passive voice. Fourth and finally, “since” always refers back to time, while “for” can refer to both time and space.

For – Used to introduce a list of reasons

Since – Used to introduce a time interval

The two words have different meanings when used in a sentence. For is used to introduce a list of reasons, while since is used to introduce a time interval. The following example shows the difference:

Since John has been here, the office has been much more organized.

In this sentence, since is used to introduce a time interval. The subject, John, has been at the office for a period of time, which means that the office has been in disarray since he’s been there.

Since – Indicates a time or date

For – Indicates a purpose or aim

Since is used to indicate a time or date. For example, “since yesterday” means “since the day before yesterday.”

Example: For example, I’ve been sick since December.

Since December I’ve been sick, which is different.

Do not use for adjectives or adverbs.

Since is an adverb.
The use of for as a verb is incorrect.

For should only be used with nouns, adjectives, or articles. Since is an adverb and should only be used with verbs.

To be clear, always use since when indicating a time or date: Since last week, since 2004

When speaking about time, it is important to be clear about what you are referring to. There are two common ways to express time: for and since. Here’s a guide to help you choose the right one for your situation.

For: To refer to a specific time in the past, use “for.” For example, “I have been working for six hours today.”

Since: To indicate a point in time without specifying a date, use “since.” For example, “Since last week, I have not been sleeping well.”

Always use “since” when indicating a point in time without specifying a date. This is because dates can change, so using “for” could lead to confusion down the road. For example, if someone says “I have been working for six hours today since yesterday,” they may mean that they have been working continuously since yesterday morning. However, if someone says “I have been working for six hours since last week,” they are referring to the time period from last Friday until now.