The Second House of Men spoke an unrelated language, the Haladin tongue. This language and Taliska were not mutually intelligible.
The exact origin of Taliska is not clear, but certain is that there are both Elvish and Dwarvish (Khuzdul) influences, suggesting the Atanatári (Fathers of Men) had contacts with both peoples before arriving in Beleriand.
Other versions of the Legendarium
Taliska, unlike Tolkien's later languages, was based directly on the Germanic languages, and has a lot in common with the Gothic language, which shows that Tolkien tried to connect his mythos with the origins of Europe. Gothic was an early interest of Tolkien.
However it is possible that Taliska belongs to an older phase of his creation, put along with Qenya, Ilkorin and Gnomish. The name "Taliska" refers to the language of the Houses of Bëor and Haleth. The House of Hador spoke another language, which would eventually be conceived as Adunaic. Some words sid to be Taliska, refer to the language of the Haladin.
However later, in The Peoples of Middle-Earth "Of Dwarves and Men" Tolkien wrote that the Bëorians and Halethians did not speak related languages: The Hadorians spoke ancient Adunaic, and the Bëorians had a closely related language, but had adopted various "words and devices" from foreign Mannish languages. In this later conception, we can't know what would happen to the name "Taliska", if it should still refer to the language of the Haladin or of the Beorians, who are now unrelated.
The name is still used sometimes to refer to the common language of the houses of Beor and Hador (instead of Haleth).
A rather complete grammar and syntax of Taliska is known to exist, but despite work by Tolkienists this has as of 2005 not yet been published.