omokage ya oba hitori naku tsuki-no tomo

This is a haiku by Basho. Basho composed this on his 1688 journey to what is now Nagano Prefecture, which is the location of a Mount Obasute, also known as Mount Sarashina, connected to the legend of old-woman-abandonment: Ubasute. That is this woman, alone, and with the moon as her only companion, and Basho imagines himself watching the moon with her somehow. There is a Noh drama on this subject, and see Yoshitoshi's painting below.

The compound omo-kage, usually means a trace or vestige, a memory, a "face-shadow," although it can also mean "face." I saw one version which translated this as "apparition," rather than face. There are some wonderful comments here: Sarashinayama, Kamurikiyama. Reading those comments convinced me that we cannot just say "face" in English as if there were not more going on here; there is a lot going on! So, I was more free in this translation than usual.

The verb is naku, なく, a godan verb.

her face a shadow:
old woman weeping alone,

moon's friend

俤や姥ひとりなく月の友
omokage ya oba hitori naku tsuki-no tomo

omokage ya
    face-shadow!
oba hitori naku
    the old woman, alone, weeps
tsuki-no tomo
    moon's friend

俤 omo kage ~ face-shadow

や ya
姥 oba ~ old woman.
ひとり hitori ~ alone.
なく naku ~ weep, sob.
月 tsuki ~ moon.

の no
友 tomo ~ friend.

The Moon at Obasute-yama

 by Yoshitoshi

(You can see the man carrying his mother up to the mountain,

and there's the moon!)

Because I am struggling with this translation, here are some more:

her face--

an old woman weeping alone

moon as companion

(translator: David Barnhill)

her face!

an old woman weeping

moon her companion

(translator's name unknown)

A frail shadow

The old mother cries alone

Friend of the moon

(translator's name unknown)

Now I see her face,

the old woman, abandoned,

the moon her only companion

(translator: "rei fú")

Mount Obasute

the image shows

an old woman weeping alone

my friend the moon

(Jane Reichhold)

In imagination,

An old woman and I

Sat together in tears

Admiring the moon. 

(translator's name unknown)

In my dream, an old woman and I sat together,
tears streaming down our faces,
admiring the moon .

(translator's name unknown)