Compulsory vs That's mandatory
When to use each in English, with meaning, register, and examples.
Compulsory
FormalTop 5,000 (fairly common)B2adjective
That's mandatory
Top 1,000 (very common)
Most formal: CompulsoryMost common: That's mandatory
| Compulsory | That's mandatory | |
|---|---|---|
| Pronunciation | 🇬🇧 /["/kəmˈpʌlsəri/"]/🇺🇸 /["/kəmˈpʌlsəri/"]/ | 🇬🇧 //ˈmæn.də.tər.i//🇺🇸 //ˈmæn.dəˌtɔr.i// |
| Meaning | Something that must be done or followed. | It's necessary or required. |
| Example | English is a **compulsory subject** at this level. | Attendance at the training session is mandatory. |
| Register | Formal | Neutral |
| How common | Top 5,000 (fairly common) | Top 1,000 (very common) |
| CEFR level | B2 | - |
| Part of speech | adjective | |
| Collocations | compulsory education, compulsory attendance, compulsory courses, compulsory insurance | mandatory rules, mandatory requirements, mandatory attendance |
| Antonyms | optional, voluntary, discretionary | optional, voluntary, discretionary |
| Common mistakes | Confused with 'optional'; it means the opposite., Often misspelled as 'compolsory'., Used incorrectly as an adverb; it is an adjective. | Used when the requirement is not serious., Confused with 'optional' meaning it’s not necessary., Saying it in an overly casual way. |
| Usage notes | Used in formal contexts, often in legal or academic settings. Avoid using in casual conversation; instead, use 'required' or 'mandatory' in those contexts. | Use in situations where following a rule is important. Avoid in casual conversations. |
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Frequently asked questions: Compulsory vs That's mandatory
What's the difference between Compulsory and That's mandatory?
Compulsory: Something that must be done or followed. That's mandatory: It's necessary or required.
Which is more formal: Compulsory and That's mandatory?
Compulsory is the most formal of these.
Which is more common: Compulsory and That's mandatory?
That's mandatory is the most common in everyday English.
Can you show an example of each?
Compulsory: English is a **compulsory subject** at this level. That's mandatory: Attendance at the training session is mandatory.
Can I use Compulsory and That's mandatory interchangeably?
Not always. Compulsory and That's mandatory 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.