You’re correct in saying that “when it comes to,” “in terms of,” and “about” are similar in meaning, for they all convey the sense of “with regard to” or “concerning” something. They have different shades of meaning, though, and there are really no hard-and-fast rules on their usage. The choice among them largely depends on the chosen or habitual tone of voice—the so-called “language register”—of the writer or speaker.
Let’s start with the preposition “about.” It’s obviously the no-frills, no-nonsense, direct-to-the-point choice when you want to refer to something very quickly: “
About the inconsiderate thing I said last night, I really didn’t mean it.” There are several close synonyms of “about,” the most common of which are “concerning,” “regarding,” “as regards,” and “with regard to,” but using them can make that same statement unnatural-sounding and ponderous. In particular, to say “
Concerning the inconsiderate thing I said last night, I really didn’t mean it” sounds officious and bureaucratic, and to say “
With regard to the inconsiderate thing I said last night, I really didn’t mean it” sounds like legalese or lawyer talk. I think you’ll agree that neither is the way to express yourself if you want to sound natural and unaffected.
As to “in terms of,” it’s an idiomatic expression that means “as measured or indicated by” in its original mathematical sense, and “in relation with,” “with reference to,” or “on the basis of” in its wider sense. Using it in its original sense gives a patina of precision and accuracy to statements, as in “Fifty years is a very short period
in terms of evolutionary time, but a manageable interval for population geneticists.” In contemporary usage, however, “in terms of” is often loosely used in the sense of “regarding,” as in “The couple’s relationship
in terms of intimacy is now practically zero.”
Much more idiomatic than both “about” and “in terms of” is the expression “when it comes to.” It means “when the subject being discussed is a particular thing,” and is often used as a grammatical transition to a different topic or a new aspect of the topic being talked about. Typical of its usage is effecting a change of subject, as in this statement: “In mathematics my professor is nothing less than a wizard.
When it comes to social interaction skills, however, he is a hopeless incompetent.”
In present-day usage, however, “when it comes to” is now often used to mean simply “about,” “as to,” “as for,” “in relation to,” “speaking of,” or “on the matter of.” Note that the sense of transition in “when it comes to” is no longer as evident in this Canadian Press news report: “Statistics Canada says people over 65 use the Internet more than they did a decade ago, but there’s still a wide generation gap
when it comes to videos and music.”
Indeed, that sense of transition is sometimes dispensed with altogether in the journalistic usage of “when it comes to,” which retains only the sense of “about.” This is the case in this sentence that starts a news report in
The Guardian in the UK: “
When it comes to air pollution, the long-suffering residents of Beijing tend to think they have seen it all. But this weekend, instruments measuring the levels of particulate matter in the city’s famously noxious air broke all records.”
So when uncomfortable or doubtful about using the various idiomatic variations of “about,” stick to “about.”
