Learn Hardcore Greek: Λέμε ότι είναι πιο ασφαλές να έχει ο κάθε ποδηλάτης κράνος και φως στο ποδήλατο, για την ασφάλεια όλων. - We say that it is safer for every cyclist to have a helmet and a light on the bicycle, for everyone’s safety.

Literally, it means “we say”, but in Greek this “we” is often used impersonally or generically, similar to English “we say / people say / one says / it is said”.
In this sentence, Λέμε can be understood as:

“We say that…”
or more naturally: “We (generally) say / We consider that it is safer…”

So the speaker is either:

speaking on behalf of a group (“we think / we say”), or
using the common Greek style where λέμε introduces a general opinion or rule.

What is the function of ότι in this sentence, and how is it different from πως or να?

Here ότι is a conjunction meaning “that” (introducing a subordinate clause).

Λέμε ότι… = “We say that…”
The clause ότι είναι πιο ασφαλές… is the object of the verb λέμε.

Differences:

ότι and πως can both mean “that” in many cases:
- Λέμε ότι είναι… ≈ Λέμε πως είναι…
  In spoken Greek, πως sounds a bit more informal/colloquial; ότι is more neutral/standard.
να is different: it usually introduces a subjunctive clause (an action, wish, possibility, purpose):
- να έχει ο κάθε ποδηλάτης… = “for each cyclist to have…”

So in the sentence:

ότι introduces what we say.
να introduces what is safer to happen (that each cyclist have a helmet and a light).

Why is ασφαλές in the neuter form (πιο ασφαλές) and not masculine or feminine?

Ασφαλές is the neuter singular form of the adjective ασφαλής (safe).

In the structure είναι πιο ασφαλές να…, Greek uses the neuter singular because the “thing” that is safer is not a concrete noun, but an entire action / situation expressed by the να‑clause:

είναι πιο ασφαλές να έχει ο κάθε ποδηλάτης κράνος και φως…
= “it is safer for every cyclist to have a helmet and a light…”

In Greek:

When the subject is an abstract idea, statement, or whole clause, adjectives often appear in neuter singular.
It’s similar to English using “it” in “It is safer to…”. The “it” corresponds to the implicit neuter subject in Greek, and ασφαλές matches that neuter “it”.

How does πιο ασφαλές work grammatically? Could we say ασφαλέστερο instead?

Πιο ασφαλές literally means “more safe” = “safer”.

Grammar:

πιο = “more” (comparative marker)
ασφαλές = “safe” (neuter singular form of ασφαλής) So πιο ασφαλές is the periphrastic comparative: more safe → safer.

You can also form a single‑word comparative:

ασφαλέστερο = “safer”, also neuter singular.

In modern Greek:

Both πιο ασφαλές and ασφαλέστερο are grammatically correct.
πιο + adjective is more common and more natural in everyday speech and writing. So you could say:
είναι πιο ασφαλές να…
or
είναι ασφαλέστερο να…

with almost the same meaning and style, but the first is more typical in modern usage.

What is να έχει doing here? Why να and why έχει (and not something like an infinitive)?

Modern Greek does not use an infinitive like English “to have”. Instead, it uses να + subjunctive form of the verb.

να: particle introducing a subjunctive clause (actions that are desired, possible, recommended, etc.)
έχει: 3rd person singular, present subjunctive of έχω (to have).
(Formally it looks like the present indicative, but the να makes it subjunctive in function.)

So να έχει ο κάθε ποδηλάτης κράνος και φως… means:

“for each cyclist to have a helmet and a light…”
or literally, “that each cyclist have a helmet and a light…”

The whole clause να έχει ο κάθε ποδηλάτης… acts as the complement of είναι πιο ασφαλές:
είναι πιο ασφαλές [να έχει ο κάθε ποδηλάτης…]
= “It is safer [for each cyclist to have…]”

Why is the subject ο κάθε ποδηλάτης placed after να έχει instead of before it?

Greek word order is more flexible than English. The subject can appear:

before the verb: να έχει ο κάθε ποδηλάτης…
or after the verb: να έχει ο κάθε ποδηλάτης… (this is actually “after” in both cases; alternative is ο κάθε ποδηλάτης να έχει…)

In your sentence we have:

να έχει ο κάθε ποδηλάτης κράνος και φως…

You could also say:

να έχει κάθε ποδηλάτης κράνος και φως…
ο κάθε ποδηλάτης να έχει κράνος και φως…

All are grammatical. The chosen order:

keeps the flow verb → subject → objects, which is very natural in modern Greek, especially in embedded clauses.
adds a slight emphasis on the action να έχει (to have), then specifies who has it.

Meaning does not change significantly; it’s mostly a matter of style and rhythm.

Why is there an article in ο κάθε ποδηλάτης? In English we just say “every cyclist”, not “the every cyclist”.

In Greek, the word κάθε (“each / every”) often appears with the definite article, especially with singular countable nouns:

ο κάθε ποδηλάτης = “each/every cyclist”
κάθε ποδηλάτης is also possible, meaning almost the same thing.

Nuance:

κάθε ποδηλάτης = more neutral “every cyclist”.
ο κάθε ποδηλάτης = can feel a bit more specific or emphatic: each individual cyclist, any given cyclist.

The article ο here:

agrees with ποδηλάτης (masculine singular),
does not translate directly into English,
is part of a very common Greek pattern ο κάθε + noun.

So you should usually translate ο κάθε ποδηλάτης simply as “every cyclist” or “each cyclist”, without adding “the” in English.

Why do κράνος and φως have no articles? Why not ένα κράνος or το κράνος?

Κράνος (helmet) and φως (light) are direct objects of έχει, and in this context they refer to what a cyclist should generally have, not to a specific, identified helmet or light.

In Greek:

When talking about things in a general, non‑specific way, especially in rules, habits, or “what someone typically has”, it’s common not to use an article:
- έχω αυτοκίνητο = “I have a car”
- πίνω καφέ = “I drink coffee”

Here:

να έχει … κράνος και φως = “to have a helmet and a light” (in general)
Using ένα κράνος / ένα φως would emphasize “one helmet / one light”, which is possible, but less necessary here.
Using το κράνος / το φως would point to some specific helmet/light already known, which is not the case.

So the article‑less form expresses the idea “cyclists should have helmet and light (as equipment)” in a general sense.

What does στο ποδήλατο literally mean, and what is στο?

Στο is a contraction of:

σε (in, at, on, to) + το (the, neuter singular article)

So:

στο ποδήλατο = σε + το ποδήλατο
Literally: “on the bicycle” / “on the bike”.

In context:

φως στο ποδήλατο = “a light on the bicycle”
(practically: a light mounted on the bike)

We often translate this simply as:

“a light on the bike” or “a bike light”.

The article το is used because ποδήλατο (bicycle) is neuter, and here we refer to the cyclist’s bike in a generic but still “possessive/specific” way; Greek often uses the article where English might omit it.

What does για την ασφάλεια όλων mean grammatically, especially όλων?

Για την ασφάλεια όλων breaks down like this:

για = “for”
την ασφάλεια = “the safety” (feminine singular, accusative)
όλων = “of all / of everyone” (genitive plural of όλος = all)

So literally:

για την ασφάλεια όλων = “for the safety of all (people)”

Όλων is in the genitive case because it depends on ασφάλεια:

η ασφάλεια όλων = “the safety of all”

In natural English, we usually translate this part as:

“for everyone’s safety”
rather than the more literal “for the safety of all”.

Why is there a comma before για την ασφάλεια όλων? Is that a separate clause?

The comma before για την ασφάλεια όλων separates the main statement from a phrase of purpose / reason.

Structure:

Λέμε ότι είναι πιο ασφαλές να έχει ο κάθε ποδηλάτης κράνος και φως στο ποδήλατο,
→ main clause: what “we say” and what is “safer”
για την ασφάλεια όλων.
→ explanatory phrase: for everyone’s safety.

Grammatically, για την ασφάλεια όλων is:

not a full clause (there is no verb),
but a prepositional phrase giving the reason / purpose for the recommendation.

The comma:

helps readability,
is very natural here, similar to English:
“It is safer if every cyclist has a helmet and a light on the bicycle, for everyone’s safety.”