Learn Hardcore Greek: Όταν αγνοείς τους κανόνες και δεν ακολουθείς τις οδηγίες, βάζεις τον εαυτό σου και τους άλλους σε κίνδυνο. - When you ignore the rules and don’t follow the instructions, you put yourself and others in danger.

αγνοείς, ακολουθείς, βάζεις all end in -εις, which is the 2nd person singular present ending (you).
So αγνοείς by itself means you ignore, ακολουθείς means you follow, βάζεις means you put.

You can say εσύ αγνοείς, but that is only used for emphasis, like saying you (in particular) ignore….

What does όταν mean here, and how is it different from αν?

In this sentence, όταν means when / whenever and introduces a general, repeated situation:

Όταν αγνοείς… βάζεις… = When(ever) you ignore…, you put…

Difference from αν:

όταν = when (in time), especially for regular or sure events
- Όταν βρέχει, μένω σπίτι. = When it rains, I stay home.
αν = if (condition), maybe it happens, maybe not
- Αν βρέξει, θα μείνω σπίτι. = If it rains, I will stay home.

Here we are talking about a general rule (what happens whenever you do this), so όταν is the natural choice.

What tense/aspect are αγνοείς, ακολουθείς, and βάζεις, and what does that imply?

All three verbs are in the present tense, active voice, imperfective aspect, indicative mood.

αγνοείς – you ignore
(δεν) ακολουθείς – (do not) follow
βάζεις – you put

Because they are present imperfective, they express:

a general truth / habit: When you (generally / in general) ignore…
in English this can be translated either with a simple present (you ignore) or a present progressive (you are ignoring) depending on context.

Here the meaning is general (a rule or warning), so simple present in English is best.

Why do we have τους κανόνες and τις οδηγίες? What are these forms?

τους and τις are definite articles in the accusative plural, agreeing with the nouns:

τους κανόνες = the rules
- τους: masculine, accusative plural
- κανόνες: masculine, accusative plural (from ο κανόνας)
τις οδηγίες = the instructions
- τις: feminine, accusative plural
- οδηγίες: feminine, accusative plural (from η οδηγία)

They are in the accusative because they are direct objects of the verbs:

αγνοείς (τι;) τους κανόνες – you ignore what? the rules
δεν ακολουθείς (τι;) τις οδηγίες – you do not follow what? the instructions

Why is it τον εαυτό σου for yourself, even if the person is female?

τον εαυτό σου literally means your self and is the standard reflexive form for yourself.

εαυτός is grammatically masculine in Greek, no matter whether the real person is male or female.
That’s why the article is τον (masculine, accusative singular): τον εαυτό.
The possessive σου (your) shows whose self it is.

So a woman would still say:

Βάζω τον εαυτό μου σε κίνδυνο. = I put myself in danger.

The gender of εαυτός is grammatical, not biological; it does not change with the speaker’s gender.

Why is it σε κίνδυνο and not something like στον κίνδυνο or έναν κίνδυνο?

σε κίνδυνο is a fixed, idiomatic way in Greek to say in danger / into danger.

σε
- accusative often expresses a state or condition:
  - σε κίνδυνο = in danger
  - σε ησυχία = in peace / quiet
  - σε δυσκολία = in difficulty

Normally you do not use an article here; σε κίνδυνο (without article) sounds natural and generic, like English in danger, not in the danger.

Forms like στον κίνδυνο would mean into the (specific) danger and are unusual in this abstract warning sentence.

Why is the negative δεν used before ακολουθείς and not μην?

Modern Greek uses two main negative particles:

δεν for the indicative mood (normal statements and questions)
μη(ν) mainly for the subjunctive and imperative (wishes, commands, prohibitions etc.)

Here we have a factual statement:

(όταν) δεν ακολουθείς τις οδηγίες = (when) you do not follow the instructions

It is a normal indicative sentence, so δεν is correct.

Example contrast:

Μην ακολουθείς τις οδηγίες. = Don’t follow the instructions. (negative command → μην)
Δεν ακολουθείς τις οδηγίες. = You don’t follow the instructions. (statement → δεν)

Can the word order in βάζεις τον εαυτό σου και τους άλλους σε κίνδυνο be changed?

Greek word order is flexible, but some orders are more natural.

The most neutral here is what you see:

βάζεις [τον εαυτό σου και τους άλλους] [σε κίνδυνο]

You could also say:

βάζεις σε κίνδυνο τον εαυτό σου και τους άλλους.

Both are fine. Putting σε κίνδυνο right after βάζεις slightly emphasizes the dangerous state, while the original order flows more smoothly.

More unusual (but still possible in certain emphatic contexts):

Τον εαυτό σου και τους άλλους βάζεις σε κίνδυνο. (emphasis on τον εαυτό σου και τους άλλους)

For a learner, sticking to the original or to βάζεις σε κίνδυνο τον εαυτό σου και τους άλλους is safest.

What is the role of τους άλλους in the sentence, and why is it in that form?

τους άλλους means the others (other people) and is another direct object of βάζεις:

βάζεις (ποιον;) τον εαυτό σου και (ποιον;) τους άλλους
= you put (whom?) yourself and (whom?) others

Grammatically:

άλλους is masculine, accusative plural (from ο άλλος = the other)
τους is the matching article: masculine, accusative plural

So τον εαυτό σου and τους άλλους are two coordinated objects of the same verb βάζεις.

What is the difference between κανόνες and νόμοι in Greek?

Both can translate as rules / laws, but they are used differently:

κανόνες = rules, regulations, guidelines
- classroom rules, safety rules, game rules, social rules
- κανόνες κυκλοφορίας = traffic rules
νόμοι = laws in the legal sense, passed by a government/parliament
- νόμοι του κράτους = the laws of the state

In this sentence, κανόνες fits better because we’re usually talking about rules and instructions (e.g. safety rules, lab rules), not formal laws.

Why are οδηγίες (instructions) in the plural? Could you use the singular οδηγία instead?

In Greek, οδηγίες is very commonly used in the plural to mean a set of instructions:

οι οδηγίες χρήσης = the instructions for use, user manual
δώσε μου οδηγίες = give me instructions

Using the singular η οδηγία is possible but has a more technical or bureaucratic feel (an individual directive, guideline, regulation).

In this general safety sentence, τις οδηγίες in the plural feels natural and refers to all the instructions you are supposed to follow.

Could you replace αγνοείς with another verb like παραβλέπεις? Would the meaning change?

Yes, there are near‑synonyms, but each has a nuance:

αγνοείς = you ignore / you act as if you don’t know / you disregard
(can also mean you are unaware of, depending on context)
παραβλέπεις = you overlook, you disregard (often consciously)
αψηφάς = you defy, you treat something as unimportant

You could say:

Όταν παραβλέπεις τους κανόνες…
Όταν αψηφάς τους κανόνες…

They keep the overall meaning (you don’t respect the rules), but:

αγνοείς is the most neutral and common here.
παραβλέπεις and αψηφάς sound slightly more formal or stronger (especially αψηφάς: you defy the rules).

The original αγνοείς is the best all‑purpose choice for a general warning like this.