Article at the Beginning of a Clause

Instead of saying, chapter 2b:
Dikaiopolis looks towards his slave; but Xanthias is not there:
ὁ Δικαιόπολις βλέπει πρὸς τὸν δοῦλον· ὁ δὲ Ξανθίας οὐ πάρεστιν.
we would normally say in English, replacing the noun by a pronoun:
Dikaiopolis looks towards his slave, but he is not there,
and in Greek,
ὁ Δικαιόπολις βλέπει πρὸς τὸν δοῦλον· ὁ δὲ οὐ πάρεστιν.
Provided the subject of the 2nd clause is mentioned in the 1st, we replace the noun by a pronoun (slave - he) in English, the Greeks just drop the noun and use only the article.
Further Examples
Philip calls his dog, but it doesn't listen.
ὁ μὲν οὖν Φίλιππος καλεῖ τὸν κύνα, ὁ δὲ οὐκ ἀκούει.
The master goads the oxen, but they no longer pull the plough.
ὁ δεσπότης κεντεῖ τοὺς βοῦς, οἱ δὲ οὐκέτι ἕλκουσι τὸ ἄροτρον.
The slave looks at the stone, but it is so big it isn't possible to lift it.
ὁ δοῦλος βλέπει πρὸς τὸν λίθον· ὁ δὲ οὕτω μέγας εστίν, ὥστε οὐ δυνατόν ἐστιν αἴρειν αὐτόν.
 
Make the following more elegant in Greek:
(and translate the article)
 
  1. ἡ Μυρρίνη λέγει· μὴ φλυάρει, ὦ Μέλιττα, καὶ μὴ σκαιὰ ἴσθι.
    ἡ δὲ Μέλιττα οὐκ ακούει, πταίει οὖν καὶ θραύει τὴν ὑδρίαν.
    How would you translate the article τήν in this sentence?
  2. ὁ Δικαιόπολις λέγει· τί οὐ πονεῖς, ὦ Χανθία;
    ὁ δὲ Χανθίας λέγει· μὴ οὕτω χαλεπὸς ἴσθι, ὦ δέσποτα, ἤδη πάρειμι καὶ συλλαμβάνω (βοηθῶ).
  3. ὁ Δικαιόπολις λέγει· ἵλαος ἴσθι, ὦ Δήμητερ, καὶ πλήθυνε τὸ σπέρμα.
    ἡ δὲ Δημήτηρ οὔτε αἰεὶ ἵλεώς ἐστιν, οὔτε ἀεὶ πληθύνει τὸ σπέρμα.
    (ἵλαος and ἵλεως are interchangeable.)
  4. ὁ μὲν Ἄργος τὸν λαγὼν διώκειν ἐθέλει· ὁ δὲ λαγὼς οὕτω ταχέως τρέχει, ὥστε δι' ὀλίγου οὐ δυνατόν ἐστιν ὁρᾶν αὐτόν.