This is an exercise in translating. I mostly sourced it from other previous translations.

Theseus
Deep, deep beneath the earth,
Let me go and make my home in the darkness
for I have lost you, dearest companion.
Your death has destroyed much more than yourself.
[Addressing the attendants pleadingly]
Will any of you tell me what happened?
[Angrily]
Or does my palace keep you useless rabble for nothing?
[He turns away, speaking more to himself]
Oh, the grief that I feel! Past utterance, past endurance,
I am lost.
My children are motherless and my house is undone.
You left us, you left me!
You, dearest and best of all women that
the dazzling sun beholds, or the starry radiance of the night.

Θησεύς
τὸ κατὰ γᾶς θέλω, τὸ κατὰ γᾶς κνέφας
μετοικεῖν σκότῳ θανών, ὦ τλάμων,
τῆς σῆς στερηθεὶς φιλτάτης ὁμιλίας:
ἀπώλεσας γὰρ μᾶλλον ἢ κατέφθισο.
†τίνος κλύω† πόθεν θανάσιμος τύχα,
γύναι, σὰν ἔβα, τάλαινα, κραδίαν;
εἴποι τις ἂν τὸ πραχθέν, ἢ μάτην ὄχλον
στέγει τύραννον δῶμα προσπόλων ἐμῶν;
ὤμοι μοι < > σέθεν,
μέλεος, οἷον εἶδον ἄλγος δόμων,
οὐ τλητὸν οὐδὲ ῥητόν. ἀλλ᾽ ἀπωλόμην:
ἔρημος οἶκος, καὶ τέκν᾽ ὀρφανεύεται.
<αἰαῖ αἰαῖ,> ἔλιπες ἔλιπες, ὦ φίλα
γυναικῶν ἀρίστα θ᾽ ὁπόσας ὁρᾷ
φέγγος θ᾽ ἁλίοιο καὶ νυκτὸς ἀ-
στερωπὸν σέλας.

Based on previous translations by Gilbert Murray (1902), Moses Hadas (1936), David Grene (1942), Philip Vellacott (1953), A.S. Way (1956), and James Morwood (1998). Greek text from Perseus.