When starting a sentence with the word "since", add a comma after the first clause (group of words containing a subject and a verb).
When starting a sentence with the word "since", add a comma after the first clause (group of words containing a subject and a verb).
Since Mary is a doctor, she can prescribe drugs.
Since Mary is a doctor she can prescribe drugs.
We do not generally need a comma before "since" in mid-sentence.
I should skip dessert since I'm trying to lose weight.
I've been studying German since 2020.
Contents
1. How to Use 'Since' in a Sentence
"Since" can be:
- A preposition to refer to a time in the past. Prepositions are followed by a noun or a pronoun (e.g., "I've been married since 2015.")
- A subordinating conjunction to explain the reason for something (e.g., "My brother can achieve it since he has experience."), or to indicate a period from a time in the past ("I've been doing this since I arrived here.") Note that subordinating conjunctions, unlike prepositions, are followed by a subject and a verb.
- An adverb to mean "ago" or between then and now (e.g., "She went to the mall this morning, and I haven't seen her since.")
2. Commas in the Middle of a sentence
In the middle of a sentence, we do not commonly use a comma in front of "since".
I'd like to travel to Japan since its culture is truly unique.
It's been raining since yesterday.
Albert has lived in Rome since 2015.
Isabella has been looking for a job since she left school.
I wonder where my niece is. I haven't seen her since Tuesday.
There are particular situations, however, where commas may be required. For example, use commas to set apart non-essential information.(1)
Alice is planning to return to Madrid, maybe next month, since she has developed an emotional attachment to the Spanish culture.
I love her, despite our relationship stumbles, since she has been respectful and patient.
The Spanish government debt, already high since the financial crisis, exploded during the 2020 debacle.
3. Starting a Sentence with 'Since'
As mentioned before, we can use "since" to introduce a group of words containing a subject and a verb (clause).
Since my sister is an excellent cook, she prepared a delicious meal.
In this situation, if the clause introduced by "since" comes at the beginning of a sentence, we must add a comma after the first clause.
Since I want to learn a new language, I registered for a Chinese course.
Since I want to learn a new language I registered for a Chinese course.
More examples:
Since they're going to arrive next week, we have plenty of time to prepare for the meeting.
Since copper is still the material of choice for electric power, the demand of copper is growing by leaps and bounds.
Since the current situation seems a perfect setup for yield curve control, the European Central Bank will probably implement this policy next year.
Instead of introducing a clause, you can use "since" to introduce a noun phrase. Phrases, unlike clauses, do not contain a subject and a verb.
Since 1980 the US GDP has been declining.
The comma after short introductory phrases like these can be easily omitted if the sentence is clear.(2)
Since then I have been learning marketing.
Since 2018 Rebecca has been working here.
4. References
(1) Strunk JR., William; White, E.B. The Elements of Style. Chapter 1 - Elementary Rules of Usage.
(2) Kaufman, Lester; Straus, Jane. The Blue Book of Grammar and Punctuation. Chapter 2 (punctuation).