Πιάνω το λουρί του σκύλου πιο δυνατά όταν έχει πολλή κίνηση.

In Greek, the verb ending usually already shows the subject, so πιάνω by itself means I hold / I grab.

• πιάνω = I hold / I grab
• πιάνεις = you hold
• πιάνει = he / she / it holds

Because of that, εγώ is often left out unless the speaker wants emphasis, contrast, or clarity.

Here πιάνω means something like I hold, I grab, or I grip. In this sentence, the most natural idea is I hold the dog’s leash more tightly.

πιάνω is a very common verb and can have several meanings depending on context, such as:

• grab
• catch
• take hold of
• touch on / reach in some other contexts

Here it clearly refers to physically holding the leash.

Greek uses the definite article very often, more often than English does. So το λουρί means the leash.

In English, we might sometimes say I hold my dog’s leash, but in Greek it is very natural to say the leash of the dog:

• το λουρί = the leash
• του σκύλου = of the dog / the dog’s

So the full phrase means the dog’s leash.

του σκύλου is in the genitive case, which is often used to show possession.

• ο σκύλος = the dog
• του σκύλου = of the dog / the dog’s

So:

• το λουρί του σκύλου = the dog’s leash

This is one of the most basic uses of the genitive in Greek.

Greek often expresses possession differently from English. Here the sentence simply says the dog’s leash without explicitly saying my dog’s leash.

That does not mean it cannot refer to your own dog. Context usually makes that clear. If someone wanted to be more explicit, they could say something like:

• το λουρί του σκύλου μου = my dog’s leash

But in many everyday situations, του σκύλου is enough.

Here πιο δυνατά is best understood as more tightly, more firmly, or harder.

A key point is that δυνατά is functioning as an adverb, describing how the leash is being held.

• δυνατός / δυνατή / δυνατό = strong
• δυνατά = strongly / loudly / hard, depending on context
• πιο δυνατά = more strongly / more firmly / harder

So Greek uses πιο δυνατά where English would naturally say more tightly or more firmly.

Because it describes the action πιάνω rather than the noun λουρί.

Compare:

• δυνατό λουρί = a strong leash
  Here δυνατό is an adjective describing the leash.
• πιάνω πιο δυνατά = I hold more firmly
  Here δυνατά describes how I hold it, so it works as an adverb.

This is very common in Greek: a neuter plural-looking form like δυνατά can function adverbially.

Because κίνηση is a feminine singular noun, and πολλή has to agree with it.

• η κίνηση = the traffic / movement / bustle
• πολλή κίνηση = a lot of traffic / heavy traffic

Greek adjectives and adjective-like words usually agree with the noun in gender, number, and case.

So:

• πολύ νερό = a lot of water because νερό is neuter
• πολλή κίνηση = a lot of traffic because κίνηση is feminine

In this sentence, κίνηση most naturally means traffic.

The basic meaning of κίνηση is movement, but in everyday Greek it is very commonly used for:

• traffic
• busy movement of cars
• sometimes general bustle / activity

So όταν έχει πολλή κίνηση usually means when there is heavy traffic.

This is an impersonal everyday Greek expression. Literally, έχει πολλή κίνηση looks like it has a lot of traffic, but the real meaning is:

• there is a lot of traffic
• traffic is heavy

No specific person is the subject here. Greek often uses έχει in this kind of general expression.

So:

• όταν έχει πολλή κίνηση = when there is heavy traffic

Yes. όταν is the standard word for when in sentences like this.

Here it introduces a time clause:

• όταν έχει πολλή κίνηση = when there is heavy traffic

It tells us under what circumstances / at what time the speaker holds the leash more tightly.

The Greek present tense often describes habitual or repeated actions, not only actions happening right now.

So this sentence does not necessarily mean the speaker is doing it at this exact moment. It more likely means:

• I hold the dog’s leash more tightly whenever there’s a lot of traffic
• I tend to hold the dog’s leash more tightly when traffic is heavy

This is a very normal use of the present tense in both Greek and English.

Yes, that is a very natural translation.

Possible natural English versions include:

• I hold the dog’s leash more tightly when there’s a lot of traffic.
• I grip the dog’s leash tighter when traffic is heavy.
• When there’s a lot of traffic, I hold the dog’s leash more firmly.

All of these reflect the Greek well.

The given word order is natural, but Greek word order is more flexible than English word order.

This sentence is:

• Πιάνω το λουρί του σκύλου πιο δυνατά όταν έχει πολλή κίνηση.

A different order could also be possible, for example to emphasize the time clause:

• Όταν έχει πολλή κίνηση, πιάνω το λουρί του σκύλου πιο δυνατά.

That would still mean the same thing: When there is heavy traffic, I hold the dog’s leash more tightly.

Greek often changes word order for emphasis, focus, or style.

Yes, δυνατά can mean loudly in other contexts. For example:

• Μίλα πιο δυνατά. = Speak louder.

But in this sentence, because the verb is πιάνω and the object is the leash, the meaning is clearly physical force, so more tightly / more firmly is the right interpretation.

Context decides which sense of δυνατά is intended.