The Tamolan languages are:

• Inapang (dialect continuum)
  • Midsivindi
  • Itutang (Isarikan)
  • Yigavesakama
• Chini–Iski
  • Akrukay (Chini)
  • Iski (dialect continuum)
    • Romkun
    • Breri

Kominimung and Igana are said to also be Tamolan languages, but no data has been collected to establish that.

Tamolan is classified among the Ramu languages of northern Papua New Guinea.

Usher (2020) reconstructs the consonant inventory as follows:^[1]

		Bilabial	Alveolar	Palatal	Velar
Nasal		*m	*n		*ŋ
Plosive	plain	*p	*t		*k
	prenasalized	*ᵐb	*ⁿd		*ᵑg
Affricate			*ⁿdz
Fricative			*s
Liquid		*w	*ɾ	*j	*ɣ

Vowels are *i *ʉ *u *a.

Usher (2020) reconstructs the pronouns as:^[1]

	sg	du	pl
1	*uku	*aŋgʉ	*ani
2	*un	*uŋgʉ	*uni
3	*an, *ma	?	?

Plus 1sg object *na.

Proto-Tamolan–Ataitan (Proto-Guam–Moam) is very similar, and nearly identical to Proto-Moam.

• Timothy Usher, New Guinea World, Proto–Guam River