# Should there be a semicolon before "and" in this sentence?

Can someone help with me with punctuating this sentence correctly?

I attended several symposiums, workshops, and summer schools, and presented my work at various conferences.

Should the comma before "and presented" be a semicolon? Or should I consider rephrasing?

• Maybe this could avoid confusion: I presented my work at various conferences and attended several symposiums, workshops, and summer schools. Does this makes any sense? Nov 1 '15 at 6:46
• hahaha yes it does; my English isn't that bad ("Does this make any sense?") I appreciate your comment.
– asef
Nov 1 '15 at 7:06

I think that example almost works with either a comma or a semi-colon.

Semi-colons have (at least) two uses:

One: To combine two clauses that could each stand as a sentence on its own, without using a conjunction.

For example:

Sally saw the box. She opened it.

Two separate sentences.

Sally saw the box and she opened it.

Two clauses that could be separate sentences joined with a conjunction.

Sally saw the box; she opened it.

Two clauses that could be separate sentences joined with a semi-colon.

Your example almost fits this pattern. If you said "I presented" instead of simply "presented", then you would have two clauses that could each stand on their own. You are connecting them with a conjunction -- "and" -- so by this convention you would use a comma. You could omit the "and" and use a semi-colon instead.

Two: Semi-colons are used to separate elements in a list when the elements are themselves lists.

Consider:

We have dresses in several color combinations: red, green, and blue and yellow and orange and black, pink, and white, and brown and tan.

The sentence is confusing. How many color combinations are there? Which colors go together?

With semi-colons we can at least give some hope of deciphering it:

We have dresses in several color combinations: red, green, and blue; yellow and orange; black, pink, and white; brown and tan.

Your example appears to fall in this category. You have two lists: things you attended and things you presented. The first element of the list is itself a list. So you can separate the two elements with a semi-colon.

In this case it's not really necessary, because the presence of two verbs -- attended and presented -- should make it clear where the two lists are separated.

• Thank you. But if I used semicolon, would be still acceptable given that after the semicolon, the subject is omitted? "I attended several symposiums, workshops, and summer schools; and [I] presented my work at various conferences." Would it work even if the second clause omits the subject?
– asef
Nov 1 '15 at 6:17
• I would say: Do NOT use a semi-colon and also "and I". "... schools; and presented ..." fits the rule about using a semi-colon to just two lists. "... schools; I presented ..." fits the rule about using a semi-colon to join two independent clauses. But "... schools; and I presented ..." fits neither rule.
– Jay
Nov 1 '15 at 6:21

No, you don't need a semi-colon and no, you don't need to rephrase.

The only reason you'd need a semi-colon would be if the sentence were ambiguous without one. There is no ambiguity here because it's obvious that "presented my work at..." is not one of the things you attended, since "I attended presented my work at..." makes no sense. Of course, you could use a semi-colon even where it's not needed but people tend to use semi-colons rather rarely.

The sentence, as written, is perfectly clear and is naturally phrased, so I see no reason to rephrase it.