That description is vague enough to overlap with those of other parts of speech because what constitutes a "conjunction" must be defined for each language.
In English, a given word may have several senses and in some contexts be a preposition but a conjunction in others, depending on the syntax.
[2] The definition may be extended to idiomatic phrases that behave as a unit and perform the same function, e.g. "as well as", "provided that".
A simple literary example of a conjunction is "the truth of nature, and the power of giving interest" (Samuel Taylor Coleridge's Biographia Literaria).
A relative clause takes commas if it is non-restrictive, as in I cut down all the trees, which were over six feet tall.
The joining of two independent sentences with a comma and no conjunction (as in "It is nearly half past five, we cannot reach town before dark.")
A comma splice should not be confused, though, with the literary device called asyndeton, in which coordinating conjunctions are purposely omitted for a specific stylistic effect.
[16] Here are some examples of coordinating conjunctions in English and what they do: Only and, or, nor are actual coordinating logical operators connecting atomic propositions or syntactic multiple units of the same type (subject, objects, predicative, attributive expressions, etc.)
The most common subordinating conjunctions in English include after, although, as, as far as, as if, as long as, as soon as, as though, because, before, even if, even though, every time, if, in order that, since, so, so that, than, that, though, unless, until, when, whenever, where, whereas, wherever, and while.
Some subordinating conjunctions, when used to introduce a phrase instead of a full clause, become prepositions with identical meanings.
One conjecture is that it results from young children's being taught to avoid simple sentences starting with and and are encouraged to use more complex structures with subordinating conjunctions.