Words in Text

ὁ οὖν πατὴρ λείπει τὸ ἄροτρον

So father leaves the plough. If the οὖν  (so, therefore, never in first place) still worries you look at the following.
 

καθίζουσιν οὖν ἅμα. And so they sit together.

We had, in lesson 3a
ἅμα οὖν ὅ τε δεσπότης καὶ ὁ δοῦλος αἴρουσιν τὸν λίθον . 
ἅμα things are much easier.
 

μετὰ δὲ τὸ δεῖπνον: and after the meal,

The preposition μετά when meaning "after" is followed by the accusative case.
so "after work" will be μετὰ τὸν πόνον, 
after [seemingly] unending work: μετὰ ἀπέραντον πόνον
μετὰ τὸν βίον comes what?
μετὰ τὸν ἄροτον what after the ploughing? (Attention: ὁ ἄροτος is not τὸ ἄροτρον!)
τὸ σπείρειν τὸ σπέρμα ἐν τῷ πέδῳ the sowing of the seed of course.
We say: the sowing
The Greeks say: the to sow, i.e. they use the infinitive with the definite article (like the Germans, the Spanish, Portuguese and quite a few others.)
Fix the form, the accusative form:
μετὰ τὸ δεῖπνον 
μετὰ τὸν ἄροτον after the ploughing
ὁ ἄροτος is done with an ἀρότρῳ (dative form to express "how? by means of what?") from
τὸ ἄροτρον the plough
Any other form sounds wrong and may well convey a totally different meaning.
You don't believe me: βαδίζει μετὰ  τοῦ  δούλου  doesn't mean after the slave, but with the slave.
μετά followed by the genitive means with. Whereas followed by the accusative it means after. It does not mean "behind". That is ὄπισθεν (+genitive) in Greek. As explained lower down on this page.
 

σπεῖρε τὸ σπέρμα ἐν τῷ πέδῳ

sow the seed in the ground! where it stays till germination, so position. And position wants the dative form :
ἐν τῷ ἀγρῷ 
ὑπὸ τῷ δένδρῳ 
ἐν τῷ πέδῳ 
 

σκάπτε τοὺς λίθους καὶ ἔκφερε ἐκ τοῦ ἀγροῦ 

dig (out) the stones and carry them out of the field. See plural forms
 

μόλις δυνατόν ἐστιν ἀροτρεύειν

it is scarcely possible to plough = well nigh impossible to
     People always find:
μόλις δυνατόν ἐστιν to remember all these words
μόλις δυνατόν ἐστιν to learn this grammar
μόλις δυνατόν ἐστιν ἡσυχάζειν because of all this noise, work, all these problems...
We had in the previous lesson:
αὖθις οὖν αἴρουσιν τὸν λίθον καὶ μόλις ἐκφέρουσιν αὐτὸν ἐκ τοῦ ἀγροῦ
What do you personally find μόλις δυνατόν
 

σὺ δέ as for you (one single you)

again opposition, contrast, balance between
    ἐγὼ μέν...   ὁ Φίλιππος δέ...   σὺ δέ...
Still unsure, want more examples?
 

τοσούτους λίθους ἐκφέρειν 

τοσοῦτοι λίθοι so many stones
τοσοῦτοι ἄνθρωποι in this confined space, help, I suffocate
τοσοῦτα δένδρα 
τοσοῦτος πόνος so much work
τοσοῦτος χρόνος 
τοσοῦτος σῖτος 
Remember:
πολὺς σῖτος    a lot of grain (or food)
ἱκανὸς σῖτος    enough
τοσοῦτος σῖτος  so much!
 

τέλος δὲ καταδύνει ὁ ἥλιος

At long last the sun goes down
In the older edition of this Athenaze course, in lesson 1a Dikaiopolis sighed: ἀτέλεστός ἐστιν ὁ πόνος work is endless, it just goes on and on and on
In this second edition he sighs: ἀπέραντός ἐστιν ὁ πόνος, it's unending, never finished. And now: at last!
τέλος δέ 
I've finished this typing.