Όταν τραγουδάμε μαζί, συχνά γελάμε και τραγουδάμε γελώντας.

Όταν means when in the sense of whenever / every time that.

In this sentence:

• Όταν τραγουδάμε μαζί, … = When(ever) we sing together, …

It introduces a time clause describing a repeated or general situation.
It does not mean if (which would usually be αν) and it does not refer to one single event, but to a typical situation that happens again and again.

In Greek, the present tense is used both for:

• actions happening right now, and
• habitual / repeated actions (things that happen regularly).

Here it expresses a habitual situation:

• Όταν τραγουδάμε μαζί… = Whenever we sing together…
• συχνά γελάμε και τραγουδάμε γελώντας. = we often laugh and sing while laughing.

So the present here corresponds to English present simple (“we sing”, “we laugh”) used for habits and regular behavior.

Greek normally drops subject pronouns when they’re clear from the verb ending.

• τραγουδάμε = we sing
• γελάμε = we laugh

The -με ending marks 1st person plural (we). Because of that, saying εμείς τραγουδάμε would be understood as we sing and usually feels redundant unless you need to emphasize we (as opposed to someone else).

So the sentence leaves εμείς out, which is the most natural way to say it.

μαζί means together and here it modifies τραγουδάμε:

• Όταν τραγουδάμε μαζί = When we sing together

It usually comes after the verb it modifies, but it’s fairly flexible. For example, all of these are natural:

• Όταν τραγουδάμε μαζί, συχνά γελάμε…
• Όταν μαζί τραγουδάμε, συχνά γελάμε… (a bit more marked / poetic)
• Όταν τραγουδάμε, συχνά γελάμε και τραγουδάμε μαζί γελώντας.

The most neutral, everyday position is exactly what you see: verb + μαζί.

συχνά means often and it is an adverb of frequency modifying γελάμε:

• συχνά γελάμε = we often laugh

Greek adverbs like συχνά are flexible. These are all acceptable:

• συχνά γελάμε
• γελάμε συχνά
• συχνά γελάμε και τραγουδάμε γελώντας
• γελάμε και συχνά τραγουδάμε γελώντας (here it would sound more like we laugh and we often sing while laughing).

In the original sentence, συχνά placed before γελάμε sounds very natural and clearly attaches the idea of “often” to the laughing.

They come from the same verb γελάω / γελώ = to laugh, but they are different forms:

• γελάμε = present tense, we laugh (finite verb)
• γελώντας = “-ing” type form, roughly laughing (non‑finite, adverbial participle)

So:

• συχνά γελάμε = we often laugh
• τραγουδάμε γελώντας = we sing while laughing / we sing, laughing

The first states an action (we laugh), the second describes how / in what manner we sing (laughing as we sing). Greek uses forms in -ώντας (like γελώντας) very often to show an action happening at the same time as the main verb.

γελώντας is the present active adverbial participle of γελάω / γελώ (to laugh). Functionally, for learners, it’s easiest to think of it as a kind of Greek “-ing” form:

• γελώντας ≈ laughing (as in we sing, laughing)

Formed by:

1. Taking the present stem of the verb (γελά-),
2. Adding the participle ending -ώντας → γελώντας (note the accent shift).

Similar examples:

• τρέχω (I run) → τρέχοντας (running)
• μιλάω (I speak) → μιλώντας (speaking)

It usually describes an action that happens simultaneously with the main verb and often answers how / when / under what circumstances something happens.

It is a bit repetitive, but it is perfectly natural and can have a stylistic effect:

• Όταν τραγουδάμε μαζί, συχνά γελάμε και τραγουδάμε γελώντας.
  = When we sing together, we often laugh and (we) sing while laughing.

The repetition can:

• Emphasize the action of singing: it frames both the beginning and the end of the sentence.
• Make the rhythm of the sentence more expressive or playful, matching the happy mood.

You could also say, more compactly:

• Όταν τραγουδάμε μαζί, συχνά γελάμε τραγουδώντας.
• Όταν τραγουδάμε μαζί, συχνά γελάμε και γελάμε τραγουδώντας.

But the original version is natural and slightly more vivid.

Yes. Both are grammatically correct:

• τραγουδάμε γελώντας
• γελώντας τραγουδάμε

They both mean essentially we sing while laughing. The difference is very slight:

• τραγουδάμε γελώντας sticks to the pattern verb + “-ing” form (sing, laughing).
• γελώντας τραγουδάμε begins with γελώντας, giving a tiny bit more emphasis to laughing as the setting or background: laughing, we sing.

In everyday speech, τραγουδάμε γελώντας probably feels a bit more neutral.

The sentence is divided into:

1. A subordinate time clause:

   • Όταν τραγουδάμε μαζί, = When we sing together,

2. The main clause:

   • συχνά γελάμε και τραγουδάμε γελώντας. = we often laugh and sing while laughing.

Greek, like English, normally uses a comma after a subordinate clause that comes first.
Inside the main clause, και simply joins two verbs with the same subject (we laugh and we sing), so:

• συχνά γελάμε και τραγουδάμε γελώντας.

No comma is needed before και here, just as in English “we often laugh and sing while laughing” you wouldn’t add a comma before and.