Learn Hardcore Greek: Στέλνω συχνά βίντεο στη φίλη μου, αλλά στο κινητό της δεν έχει καθόλου ίντερνετ. - I often send videos to my friend female, but on her mobile there is no internet at all.

In Greek, the verb ending already shows the subject.
Στέλνω is 1st person singular (I send), so the pronoun εγώ is usually omitted unless you want to emphasize I (e.g. Εγώ στέλνω, όχι εσύ – I send, not you).

So Στέλνω συχνά βίντεο naturally means I often send videos without needing εγώ.

Why is συχνά placed after the verb (Στέλνω συχνά βίντεο) and can it go somewhere else?

Συχνά is an adverb meaning often. In Greek it usually goes:

after the verb: Στέλνω συχνά βίντεο
or between auxiliary and main verb, if there is one.

You can also say:

Συχνά στέλνω βίντεο – putting συχνά at the beginning for emphasis on how often.

All of these are natural. The most neutral positions are either:

Στέλνω συχνά βίντεο
Συχνά στέλνω βίντεο

Putting it right at the very end (Στέλνω βίντεο συχνά) is also possible but sounds slightly less standard in this short sentence.

Why is there no article with βίντεο – why not ένα βίντεο or το βίντεο?

Greek often omits the article when you speak about things in a general or indefinite way, especially direct objects in the plural or when they’re “mass-like”:

Στέλνω βίντεο = I send videos (in general / some videos).

If you say:

Στέλνω ένα βίντεο – I am sending one (specific) video.
Στέλνω το βίντεο – I am sending the video (a particular one we both know about).

In the original sentence, the idea is general and habitual: I often send videos, so there is no article.

Why is βίντεο the same in singular and plural?

Βίντεο is an indeclinable neuter noun borrowed from English. Its form does not change:

singular: το βίντεο – the video
plural: τα βίντεο – the videos

You understand if it’s singular or plural from the context or the article (το / τα, ένα / μερικά, etc.), not from the word ending itself.

What exactly is στη in στη φίλη μου, and why that form?

Στη is a contraction of:

σε (preposition: to, in, at)
- τη(ν) (feminine singular definite article: the)

So:

σε + τη = στη

You use σε to mark the indirect object (the person you send something to):

Στέλνω βίντεο στη φίλη μου = I send videos to my (female) friend.

The final -ν of την often drops before consonants, so στην φίλη becomes στη φίλη in everyday writing and speech.

Why does the possessive μου come after the noun (φίλη μου) instead of before, like in English?

In Greek, possessive pronouns usually follow the noun:

η φίλη μου – my friend
το κινητό της – her mobile
το σπίτι μας – our house

So φίλη μου literally is friend my, but that is the normal Greek order.
Putting the possessive before the noun (μου φίλη) is either ungrammatical or used rarely in very special, poetic-like expressions.

What is the difference between φίλη and φίλος?

Greek marks the friend’s gender:

ο φίλος – (male) friend
η φίλη – (female) friend

In the sentence, στη φίλη μου specifically means to my female friend.
If you wanted to say to my male friend, you’d say:

στον φίλο μου (or colloquially στο φίλο μου, dropping the final -ν).

Why is it στη φίλη μου but στο κινητό της? What’s the difference between στη and στο?

Both are contractions of σε + article, but with different genders:

σε + τη(ν) = στη → feminine singular
- στη φίλη μου – to my (female) friend
σε + το = στο → neuter singular
- στο κινητό της – on/at her mobile (phone)

So στη / στο / στον all come from σε + definite article, and they must agree in gender, number, and case with the noun that follows.

Why is μου used with φίλη but της with κινητό? Aren’t they both possessives?

Yes, both μου and της are unstressed possessive pronouns, but they refer to different people:

μου = my
της = her

So:

στη φίλη μου – to my friend
στο κινητό της – on her mobile

The subject of the sentence is I (from στέλνω), but της refers to the friend (her phone).
So you are talking about: I send videos to my friend, but her phone has no internet.

In στο κινητό της δεν έχει καθόλου ίντερνετ, who is the subject of έχει? Is it “she” or “it”?

Literally δεν έχει ίντερνετ means there is no internet / it doesn’t have internet.

Greek often uses έχει without an explicit subject in expressions of existence/availability:

Έχει ζέστη. – It is hot. (literally “has heat”)
Δεν έχει ψωμί. – There is no bread / There isn’t any bread.

Here, στο κινητό της δεν έχει ίντερνετ means on her mobile, there is no internet.
You can think of the implied subject as something like it (the phone / the situation), but in Greek you just say δεν έχει without naming it.

What does καθόλου add to the meaning in δεν έχει καθόλου ίντερνετ? Could we leave it out?

Καθόλου intensifies the negation; it means at all or not any:

δεν έχει ίντερνετ – there is no internet / she doesn’t have internet
δεν έχει καθόλου ίντερνετ – she has no internet at all / absolutely no internet

You can leave καθόλου out; the sentence will still be correct. Including καθόλου makes it stronger and more emphatic.

Why is there no article before ίντερνετ?

Like βίντεο, ίντερνετ is a borrowed indeclinable noun and is usually treated like a mass/uncountable noun:

Έχει ίντερνετ. – She/it has internet.
Δεν έχει ίντερνετ. – She/it doesn’t have internet.

You normally don’t say το ίντερνετ unless you are talking about the internet in a very specific, almost technical or contrastive way (e.g. Το ίντερνετ της εταιρείας πέφτει συνέχεια. – The company’s internet keeps going down).

In everyday speech, no article is used in this kind of sentence.

Could we change the word order in the second part, for example Δεν έχει καθόλου ίντερνετ στο κινητό της? Is there any difference?

Yes, you can say:

Στο κινητό της δεν έχει καθόλου ίντερνετ.
Δεν έχει καθόλου ίντερνετ στο κινητό της.

Both are grammatical and mean the same thing.

The original order (Στο κινητό της δεν έχει…) puts slight emphasis on στο κινητό της – on her phone as the location where there is no internet.
The order Δεν έχει καθόλου ίντερνετ στο κινητό της is more neutral and is also very common.

Is κινητό just short for κινητό τηλέφωνο? Does it always mean “mobile phone”?

Yes. The full term is κινητό τηλέφωνο (mobile telephone), but in everyday speech Greeks almost always just say:

το κινητό – the mobile (meaning mobile phone)

Depending on context κινητό alone is understood as mobile phone. Only in special technical contexts might κινητό mean something else (like “mobile” in physics, etc.), but in normal conversation it means cell phone / mobile phone.