A command is an order, or an instruction given to a computer. A comment is a remark or opinion. The general gave the command; she left a comment on the post. Both are nouns and verbs, both begin com-, and they are confused mainly by shape.
The core difference
- command — an authoritative order, control, or a computer instruction. At his command, in command of the ship, the command line, a good command of French.
- comment — a spoken or written remark, often an opinion. No comment, leave a comment, a passing comment.
The tell
Command keeps company with commander, demand and mandate — all about telling. Comment keeps company with commentary and commentator — all about saying. Software has both: you type a command and the program obeys; you write a comment and the program ignores it.
In use
- command — The captain gave the command to fire. Type the command and press enter.
- comment — He made a comment about the weather. Please leave a comment below.
Common slips
- leave a command below → leave a comment below
- the officers issued a comment to withdraw → the officers issued a command to withdraw
Commanders command; commentators comment.
Where the words come from
Command is from Latin commendare, "to entrust", reshaped by mandare "to order" — the same mand as in mandate. Comment is from Latin commentum, "an invention, a contrivance", from comminisci "to devise", which shifted to mean an explanatory note and then any remark.
Frequently asked questions
What does "a good command of English" mean?
Mastery — the ability to use the language with control. It is the control sense of command, not the order sense.
Is it "no comment" or "no command"?
No comment. It is the set phrase for declining to answer a journalist.
What is a command line?
A text interface where you type instructions for the computer to carry out. Each instruction is a command.