When someone is going to drive their car somewhere, I always used to say "drive safely" to them. Recently I was told I should say "drive safe."

(From: Would you ask someone to drive safe or to drive safely?)

Which one is correct? Similarly, is "do good" correct?

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    It irritates me when the GPS smartphone app Waze audio speech synthesizer says "Drive safe" when you select a destination. Commented Dec 6, 2014 at 2:58
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    it's utterly normal in english to use almost any form, as another, here something like adverb/adjective. you can use almost anything as a verb, noun, etc etc. it's completely commonplace to say things like "you're very chair today" or "I want to buy faster" and so on.
    – Fattie
    Commented May 20, 2015 at 8:33
  • Who told you this? A teacher? An acquaintance? Where did you hear it (what country)? Commented Aug 3, 2015 at 19:40
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    I would say that in colloquial American English, you could use either. Certainly "drive safely" is not wrong. Standard British English tends to be a lot stricter about flat adverbs (adjectives used as adverbs), and I'd be interesting in hearing what someone from the U.K. thinks. Commented Aug 3, 2015 at 19:40
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    The Texas Department of Transportation once had as its slogan "Drive Friendly," and I assume that in Cupertino, California, they say "Drive different." But for my money, "Drive safely" is the way to go.
    – Sven Yargs
    Commented Aug 3, 2015 at 20:20

12 Answers 12


"Drive safely" is the formally correct phrase.

Saying "drive safe" sounds casual and informal; however, many people do it. This is because, in general, people sometimes use the adjective form as an adverb (usually this means not adding -ly) in casual speech. It is not recommended in any formal situations.

"Do good" is a different kind of issue, because the form depends on the meaning you want to convey.

  • If "do good" means "do the right/good thing", then "do good" is the formally correct phrase.

  • If "do good" means "perform correctly/at a high level", then "do well" is the formally correct phrase. (But, as mentioned above, casually you could also say "do good" here.)

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    Superman does good. You're doing well.
    – Anthony
    Commented Jan 10, 2011 at 7:19
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    Actually both forms are correct. Safe(ly) is, in this case, an adverb. And as an adverb, it can be used either a flat adverb or not.
    – cogumel0
    Commented Nov 19, 2018 at 10:09
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    cogumel0: It's true that, in terms of linguistic grammaticality, both are fine. People use both forms every day. But in terms of which adheres to the generally accepted rules of Standard English, there is a clear distinction between the -ly form and the bare form. Except for special cases, e.g. "first", the bare adverb is seen as decidedly informal.
    – Kosmonaut
    Commented Nov 20, 2018 at 17:08
  • ' "Drive safely" is the formally correct phrase' and 'It's true that, in terms of linguistic grammaticality, both are fine' seem at odds. I think it's because of the polysemy of 'formally'. I'd put " 'drive safe' is a less formal variant of 'drive safely'; while the latter is incontrovertibly correct, the former is seen as unacceptable by some. But M-W, for instance, licenses the flat adverb.'' Commented Aug 17, 2023 at 15:33

I happened across this interesting article at The Economist, of all places, which speaks of this exact phenomenon, and notes that adverbs in adjective form have been around in English forever.

That article notes that there may be a subtle difference in meaning between "safe" and "safely," and I tend to agree. "Drive safely" more specifically refers to driving in a safe manner. "Drive safe" emphasizes the end result, being unharmed when you stop driving.

I'm often critical of poor grammatical constructions, but in this case, I think this is an acceptable phrase and does have a slightly different meaning or tone than "drive safely."

"Do good" has the unspoken meaning "Do good (things)" and generally refers to acting in a benevolent manner. If you mean to complete a task or test acceptably, you should say "Do well."


It is an old bugaboo of the grammar police that in any pairing of an adjective with its -ly-suffixed adverb -- safe, safely; slow, slowly -- the (nominal) adjective must never be used as an adverb. You may ignore this prescription.

As the OED quaintly puts the case for "safe": "Chiefly (now only) with quasi-advb force with verbs of coming, going, bringing, etc.," recording examples back to Chaucer as well as this more modern one from 1902:

Your ... man has brought us out ... safe and dry.

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    That would only be the case if the verb is used in a modal sense, i.e. it does not so much describe how something happens (in which case you would need an adverb, hence "drive safely"), as the state of the subject. Thus in your example "your man has brought us out safe and dry" safe and dry tells us something about the persons who have been brought out, not the way they were brought out. Commented Aug 3, 2015 at 21:16
  • Thus the word "quasi" in the OED's entry. They're safe, but not until they had been brought out in a safe manner.
    – deadrat
    Commented Aug 3, 2015 at 22:11
  • In your example, they are safe but there is no evidence whatsoever that the manner of their being brought was safe. He drove furiously and dangerously but we arrived safe. Or would you argue "serious" that he "drove furious and dangerous but we arrived safe"? There is a need and a place for the adverbial form and its removal merely makes for ambiguity and a depauperate prose.
    – Anton
    Commented Aug 4, 2015 at 6:12
  • @Anton I'm not advocating for the "removal" of adverbial forms; I'm not telling you that every adverb in every sentence may be replaced by its adjectival cousin; I'm telling you what is. As documented by the gold standard of historical documentation of English usage.
    – deadrat
    Commented Aug 4, 2015 at 6:26
  • In your example "safe and dry" are complements, the state of "us" resulting from being "brought out". Somewhat different than "drive safe".
    – TimR
    Commented Aug 17, 2023 at 11:16

"Be safe" but "drive safely." Safely is an adverb modifying the verb drive. Safe is an adjective that can modify a noun.

  • If "be safe" is acceptable but "drive safe" is not, what about "work safe?"
    – ghoppe
    Commented Jan 10, 2011 at 17:49
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    @ghoppe, I would interpret "work safe" as an adjective meaning "safe for work", not as any sort of command or exhortation.
    – Marthaª
    Commented Feb 15, 2011 at 5:08
  • M-W allows 'safe' as a variant of 'safely'. Commented Aug 17, 2023 at 15:32

In British English the correct usage is to use the adverbial form to modify a verb.

If someone wrote “we drove safe from London to Edinburgh” I would edit it to “safely”, first making sure that they had not stolen a safe and mistakenly omitted the definite article. No doubt there are those who would argue hotly (argue hot? Don't make me laugh!) that this is a silly old anachronism, but the use of the adjective as an adverb in the UK is likely to be lazy, sloppily informal or just plain wrong. But be careful! Some words act equally well as adverb and adjective, as in: “I am thinking straight”. And do not be misled by “we arrived safe” because safe in that sentence describes our state (safe, adjective) on arrival, not the manner (safely, adverb) of our arriving.

  • Someone has kindly edited my answer but it still reads almost as I intended it. The added distinction between the commonly used "UK English" and the grammarians' "British English" is trivial: they are synonymous.
    – Anton
    Commented Aug 5, 2015 at 15:30

"Drive safe" would possibly be used for transporting a strongbox, "drive safely" is driving in a safe manner.

"Do good" is correct, but it doesn't have the same meaning as "do well", it's doing something that is considered a good deed.


Drive safe is along the lines of 'fare well', it is a pretty generic platitude.

Drive safely is an instruction, you are telling the person to not speed, not run red lights etc.

Which you want to use depends if you think the driver is likely to cause a crash or just want to let them know that you like them being alive.

  • An Englishman living in Australia for a long time.
  • +1; this is how I understand the two phrases. But it might be worth saying where you're from, since -- judging from the rest of this page -- there seems to be a dialect difference here. (FWIW, I'm from the Upper Midwestern US.)
    – ruakh
    Commented Aug 4, 2015 at 7:27

There is a Merriam-Webster Dictionary video from the editor about this exact topic. In it "safe" in "drive safe" is classed as a "flat adverb". The editor's opinion is they used to be more common in the past, but that prescriptivist grammarians from the 18th century considered them to be a mistake, which is the possible reason for their decline. The video gives examples of some that are still to a greater or lesser extent acceptably used today:

slow (go slow)
bright (shines bright)
fast (time passes so fast)
(notice that we nearly never say time passes so fastly)

Here is a link to the video.

Accordingly, Merriam-Webster licenses the adverbial usage of 'safe':

safe [adverb]: variant of safely

And in a corresponding article:

What to Know

Both 'drive safe' and 'drive safely' are fine to use. Flat adverbs – adverbs without -ly – are common in English....

But should they [be]? In fact, the adverb 'safe' is what's called a flat adverb. That is, it's an adverb that has the same form as its related adjective – like 'safe' in 'drive safe', 'slow' in 'go slow', or 'easy' in 'take it easy'.

Flat Adverbs

Flat adverbs used to be much more common than they are now. In Robinson Crusoe, Daniel Defoe described weather that was 'violent hot'. In his famous diary, the English writer Samuel Pepys wrote that he was 'horrid angry'. But most of these adverbs have long since been abandoned. In Middle English, adverbs like these had case endings that distinguished them from their related adjectives, but those gradually disappeared. Eighteenth-century grammarians didn't even identify flat adverbs as adverbs; they considered them adjectives and the adverbial use to be a mistake.

It's these eighteenth-century grammarians that we have to thank for the still-repeated injunction that adverbs end in -ly – and for the sad lack of flat adverbs today. We still have some, but most of them compete with an -ly form: there's 'slow' and 'slowly', 'safe' and 'safely', 'bright' and 'brightly'. But then we have 'tight' and 'tightly', with 'tight' used in a few places 'tightly' is not: 'sit tight', 'sleep tight'....


In the version of British English that I speak, it would be the adverbial form - "Drive safely."


I think that 'safe' can be used as an adverb when it applies to a maintained condition. In this case, 'drive safe' would be acceptable. It grates on my ears, but the American Heritage Dictionary supports this option. Consider also 'sleep tight.'


I think in the sentence "safe" modifies the verb "drive", so if we collocate "safely", our sentence sounds more natural. for instance in context, " please, drive safely because my car is new". I understand perfectly the meaning.


This argument about what is grammatically correct about "drive safe" and "drive safely" seems to run on and on. Some people quote native speakers say "drive safe". To me it depends on which country you are native of.

I learned my English at the knee of my parents both of which were of British heritage and consequently the use of the adverb as "drive safely" is clearly the grammatically correct usage. The English language has been influenced in many countries by people who learned the language as a second language, and consequently do not necessarily get the grammar totally correct. "Drive safe" may have become acceptable in common usage, but that does not make it grammatically correct.

Many hockey players say "he played awesome." Is the song titled awesome or did the speaker mean he played in a way that was awesome?

Speaking of the word awesome, the meaning has clearly changed over the years. That's why you don't hear many older people using the word awesome. Does the event really cause you to go into a state of awe?

Similarly younger people use the word amazed in a new and different way than what it used to be used. Everything is amazing these days. It was an amazing sunrise! It was an amazing steak. How many sunrises do you have to see before they become less than amazing? Really are most of us amazed by a sunrise? It happens many mornings.

Similarly I find it difficult to be amazed by a steak. There are excellent steaks, and poor steaks, and tough steaks and burnt steaks, but are there really amazing steaks.

The new words that keep appearing in the English dictionary are there because the language is changing through usage. Quite often incorrect usage, but if used enough it become acceptable.

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    While this isn't technically incorrect, it's more of a condescending opinion in the guise of authority than an answer. The children of Brits clearly “do not necessarily get the grammer [sic] totally correct,” and it isn't just second-language speakers who use adjectives as adverbs. This would be a better answer with more evidence and less judgment. Commented Apr 30, 2013 at 21:06
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    "Drive safe" is a "flat adverb". Everybody, including Shakespeare, used flat adverbs in English centuries ago, but they have now fallen out of use in the U.K., while we Americans proudly carry on the ancient custom of sometimes using adjectives as adverbs. (O.K., I'll admit we've changed our English a lot, but y'all changed it in this case.) Commented Feb 28, 2014 at 21:45