Cool MateCompletely vs Flat out vs Totally
When to use each in English, with meaning, register, and examples.
Completely
Top 1,000 (very common)A2adverb
Flat out
InformalTop 2,000 (common)
Totally
Top 2,000 (common)B1adverb
Most common: Completely
| Completely | Flat out | Totally | |
|---|---|---|---|
| Pronunciation | 🇬🇧 /["/kəmˈpliːtli/"]/🇺🇸 /["/kəmˈpliːtli/"]/ | 🇬🇧 //flæt aʊt//🇺🇸 //flæt aʊt// | 🇬🇧 /["/ˈtəʊtəli/"]/🇺🇸 /["/ˈtəʊtəli/"]/ |
| Meaning | Totally or fully. | Completely and without stopping | Completely or very much. |
| Example | I completely forgot about the meeting today. | I am working flat out to finish this project on time. | I totally agree with your opinion on the matter. |
| Register | Neutral | Informal | Neutral |
| How common | Top 1,000 (very common) | Top 2,000 (common) | Top 2,000 (common) |
| CEFR level | A2 | - | B1 |
| Part of speech | adverb | adverb | |
| Collocations | completely agree, completely understand, completely satisfied, completely different, completely unaware | run flat out, work flat out, drive flat out, be flat out busy, go flat out | totally agree, totally awesome, totally different, totally in love |
| Antonyms | partially, incompletely, somewhat | - | partially, somewhat |
| Common mistakes | Using 'completely' without a verb or action., Confusing 'completely' with 'totally' in formal contexts., Saying 'completely' in casual situations where simpler words like 'really' might fit better. | Using 'flat out' in overly formal contexts., 'Flat out' confused with its literal meaning, thinking it's only about physical flatness., Misusing it for less intense situations. | 'Totally' is sometimes confused with 'complete.', Learners may use 'totally' in formal situations when it sounds too casual., Sometimes misused to modify nouns directly. |
| Usage notes | Use 'completely' to emphasize the totality of an action or state. It's suitable for both spoken and written English but might sound overemphasized in casual conversation. | Used informally to describe doing something to the fullest or without exception. Avoid in formal writing. | Use 'totally' to emphasize an absolute degree of something. It's neutral but can sound informal in some contexts. Avoid in very formal writing. |
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Frequently asked questions: Completely vs Flat out vs Totally
What's the difference between Completely, Flat out, and Totally?
Completely: Totally or fully. Flat out: Completely and without stopping Totally: Completely or very much.
Which is more common: Completely, Flat out, and Totally?
Completely is the most common in everyday English.
Which is more advanced: Completely, Flat out, and Totally?
Totally is the highest level, at B1, on the CEFR scale.
Can you show an example of each?
Completely: I completely forgot about the meeting today. Flat out: I am working flat out to finish this project on time. Totally: I totally agree with your opinion on the matter.
Can I use Completely, Flat out, and Totally interchangeably?
Not always. Completely, Flat out, and Totally are related and overlap in some contexts, but they differ in register, how common they are, and usage, so swapping one for another can change the meaning or tone. Check the differences above before substituting.