Breakdown of Ο νόμος λέει ότι πρέπει να φοράς κράνος όταν οδηγείς ποδήλατο.
Questions & Answers about Ο νόμος λέει ότι πρέπει να φοράς κράνος όταν οδηγείς ποδήλατο.
In Greek, the subject pronoun (like εσύ = you) is usually dropped because the verb ending already shows the person:
- φοράς = you wear (2nd person singular)
- οδηγείς = you drive/ride (2nd person singular)
So εσύ is understood from the verb ending and is not needed.
You could say:
- Ο νόμος λέει ότι εσύ πρέπει να φοράς κράνος…
but that sounds emphatic, like stressing you in particular. For a neutral, general rule, Greek leaves εσύ out.
In this sentence, ότι is a conjunction meaning that, introducing what the law says:
- Ο νόμος λέει ότι πρέπει να φοράς κράνος…
= The law says that you must wear a helmet…
ότι (without comma) = that (introduces reported speech or a clause).
ό,τι (with comma) = whatever / anything that and works like a pronoun:
- Ό,τι θέλεις. = Whatever you want.
In your sentence, only ότι (without comma) is correct.
Modern Greek no longer uses an infinitive the way English does. Instead, it uses:
- να
- subjunctive form of the verb
So where English says:
- you must wear, you have to wear
Greek says:
- πρέπει να φοράς (literally: it is necessary that you wear)
This να + verb construction is the standard way to express:
- must / have to / should / want to / can etc. when followed by a verb:
- θέλω να πάω = I want to go
- μπορώ να έρθω = I can come
- πρέπει να φοράς = you must wear
Yes, it changes the aspect, which in Greek is very important.
- φοράς = imperfective aspect (ongoing / repeated action)
- φορέσεις = perfective aspect (single, completed action)
πρέπει να φοράς κράνος
→ You must be wearing a helmet whenever you ride, as a general, ongoing rule.
If you said:
- πρέπει να φορέσεις κράνος
it would usually mean you must (at some specific moment) put a helmet on, a more one‑time, completed action—e.g. a parent telling a child right now:
Πριν φύγεις, πρέπει να φορέσεις κράνος. = Before you leave, you must put your helmet on.
For legal or general rules, imperfective (να φοράς) is the natural choice: it expresses a standing requirement.
πρέπει by itself is neutral: it is necessary / one ought to.
- In a context like a law (Ο νόμος λέει ότι πρέπει…), it is usually understood as strong obligation: must / have to.
- In softer contexts, it can feel like should:
- Πρέπει να ξεκουραστείς. = You should / ought to rest.
So here, because we are talking about the law, πρέπει is best translated as must / have to.
Greek often omits the article when talking about things in a general, non‑specific way, especially in rules, habits, and instructions.
- να φοράς κράνος
= wear a helmet / a helmet in general, not a specific one - όταν οδηγείς ποδήλατο
= when you ride a bicycle / bicycles in general
If you said:
- να φοράς το κράνος = to wear the helmet (a particular, known helmet)
- να φοράς ένα κράνος = to wear a helmet (a bit more like introducing the idea that at least one helmet is needed)
In general rules and signs, Greek prefers the bare noun without article:
- Απαγορεύεται το κάπνισμα. = Smoking is prohibited.
- Απαγορεύεται η είσοδος. = Entrance is forbidden.
- Πρέπει να φοράς κράνος όταν οδηγείς ποδήλατο.
Yes, you can say:
- Ο νόμος λέει πως πρέπει να φοράς κράνος…
In everyday modern Greek, ότι and πως (without accent: πως) are often interchangeable when they mean that and introduce reported speech:
- Μου είπε ότι θα έρθει.
- Μου είπε πως θα έρθει.
Both = He told me that he will come.
Subtle points:
- In very formal or careful writing, some prefer ότι as the standard conjunction for that, and treat πως as slightly more informal/colloquial.
- With ό,τι (with comma and accent) you must be careful, because that means whatever.
In your sentence, both ότι and πως are natural, with ότι sounding a bit more neutral/standard in writing.
Using the present tense here expresses a general, timeless statement:
- Ο νόμος λέει…
= The law says… (now, always, as long as the law is in force)
If you said:
- Ο νόμος είπε ότι πρέπει να φοράς κράνος…
it would imply that the law said this at some specific point in time (e.g. when it was passed), which is not how we usually state legal rules. For laws, rules, proverbs, and permanent facts, Greek tends to use the present:
- Το βιβλίο λέει ότι… = The book says that…
- Ο Χριστιανισμός λέει ότι… = Christianity says that…
Yes, this is normal in Greek.
- οδηγώ typically means to drive (a car, bus, etc.), but it is also used for riding and controlling vehicles like a bicycle or a motorcycle:
- οδηγώ αυτοκίνητο = drive a car
- οδηγώ μηχανάκι = ride a motorbike
- οδηγώ ποδήλατο = ride a bicycle
Other natural options for bicycles:
- κάνω ποδήλατο = I ride a bike / I go cycling
- ποδηλατώ / ποδηλατώ(ω) (more formal/literary or in specific contexts) = I cycle
In everyday speech, οδηγώ ποδήλατο and κάνω ποδήλατο are both common and idiomatic.
In this sentence:
- ο νόμος = the law
- Article ο → masculine
- Ending ‑ος is very often masculine.
- το κράνος = the helmet
- (Here it appears without article, but it would be το κράνος)
- Article το → neuter
- Ending ‑ος can also be neuter; you learn which from vocabulary.
- το ποδήλατο = the bicycle
- (Again appears without article, but would be το ποδήλατο)
- Article το → neuter
- Ending ‑ο is very common for neuter.
General patterns (with many exceptions, but still helpful):
- ‑ος → usually masculine (ο δρόμος, the road), sometimes neuter (το τέλος, the end)
- ‑ο, ‑ι → usually neuter (το σπίτι, το παιδί)
You can often see the gender from the article in context:
- ο νόμος (masc.)
- το κράνος, το ποδήλατο (neuter)
Grammatically, φοράς and οδηγείς are 2nd person singular, so literally it’s addressing one person (informally).
However, in laws, rules, and instructions, this “you” often functions as a generic you, meaning anyone who rides a bicycle. It is understood as applying to everyone.
To make it clearly plural or formal (addressing you all or sir/ma’am politely), you would use the 2nd person plural:
- Ο νόμος λέει ότι πρέπει να φοράτε κράνος όταν οδηγείτε ποδήλατο.
This is the form you would expect in more formal or official written language.
Yes, that is natural Greek and often used for emphasis:
- Πρέπει να φοράς κράνος όταν οδηγείς ποδήλατο, λέει ο νόμος.
Literally: You must wear a helmet when you ride a bicycle, the law says.
Differences in nuance:
- Ο νόμος λέει ότι πρέπει να φοράς κράνος…
→ Starts by mentioning the law, then states the rule. - Πρέπει να φοράς κράνος όταν οδηγείς ποδήλατο, λέει ο νόμος.
→ Starts with the obligation, and then adds according to the law.
Both are grammatically correct; the second makes the rule more prominent in the sentence.
In this context, όταν is best understood as when(ever) in a general, repeated sense:
- όταν οδηγείς ποδήλατο
= whenever you ride a bicycle / every time you ride a bicycle
You could also say:
- όποτε οδηγείς ποδήλατο
→ also whenever you ride a bicycle, slightly more explicitly “every time”.
Using αν (if) here would shift the meaning:
- αν οδηγείς ποδήλατο
= if you ride a bicycle (on the condition that you do it)
So:
- όταν → when / whenever (temporal)
- όποτε → whenever / every time (often a bit more explicit)
- αν → if (conditional)
In rules like this, όταν is the most natural choice.