While a period ends a sentence, a comma indicates a brief pause.
Use commas in the following cases:
- To separate words and word groups in a list that contains more than 2 items.
- To separate conjunctive adverbs (in addition, also, on the other hand, however, moreover, furthermore, for example, finally).
- To separate 2 adjectives when the order of the adjectives is interchangeable.
To determine whether a comma is needed, try to put and between the 2 adjectives — if the result makes sense, add the comma.
- To separate 2 independent clauses joined by a coordinating conjunction (and, or, but).
Do not use a comma instead of a period when speaking of 2 independent clauses. To learn more about dependent and independent clauses, see this Grammarly article.
Do not use a comma to separate correlative conjunctions (both/and, either/or, neither/nor, not only/but also). To learn more about conjunctions, see this Grammarly article.
- To separate an independent clause from an introductory phrase or introductory clause (that is, a dependent clause found at the beginning of the sentence). If a sentence starts with an independent clause followed by a dependent clause, no comma is required.
You can always tell a dependent clause/introductory phrase by the subordinating conjunctions although, since, if, before, after, unless, until, for (to), as, though, that, once, when, while and because.
- To introduce a nonrestrictive clause or phrase. You can always tell a nonrestrictive clause by the relative pronoun which.
Do not use a comma when introducing a restrictive clause. You can always tell a restrictive clause by the relative pronouns that, whose and whom.
The relative pronoun who can introduce both a restrictive and nonrestrictive clause. Who and sometimes that refer to people; that and which refer to things.
Do not use a comma when a relative pronoun is part of a prepositional phrase (such as for which, in which, on which, to whom, for whom and so on).
- Veeam Availability Orchestrator leverages the backup, replication, restore and failover capabilities of Veeam Backup & Replication. [list]
- However, to work with failover plans in VAO, you do not need to categorize clusters, hosts or storage objects. [conjunctive adverb]
- Prove recoverability with isolated, low-impact testing of VM replicas and applications they run. [interchangeable]
- Automate failover processes to eliminate error-prone manual steps. [non-interchangeable]
- The backup server is a Windows-based machine on which Veeam Backup & Replication is installed, it fills the role of the “configuration and control center”. [independent clauses]
The backup server is a Windows-based machine on which Veeam Backup & Replication is installed, and it fills the role of the “configuration and control center”. [independent clauses]
- If you need to provide credentials that the script will use to run within the guest OS, perform the following steps. [introductory clause]
- You can restart a VM from any restore point in a matter of minutes since there is no need to extract the VM from the backup file. [dependent clause]
- You can generate an invoice automatically, according to a specific schedule, which can be configured as described in section Configuring Billing Notifications. [nonrestrictive]
- Veeam Availability Orchestrator provides reporting capabilities that let enterprises document their DR plans. [restrictive]
- The user who launched the Veeam Backup & Replication console will be set as the owner of the restored object. [restrictive]