So "oibríonn" can also mean "works" in the sense of "is functioning", and not only in the sense of a human doing work?
Just to clarify: if you have 'an' plus a masculine noun beginning with a vowel, it gets a t- before it (an t-inneal). If you have 'an' plus a feminine noun beginning with an 's', the 't' gets plastered right up against it (an tsraid). Is that right?
For singular masculine nouns, that’s correct for the nominative case. For singular feminine nominative and singular masculine genitive nouns, the noun needs to begin with S followed by either a vowel, L, N, or R — one wouldn’t use e.g. an tscoil, despite scoil being feminine. Note that the “plastered T” even applies to nouns in prepositional phrases, e.g. ar an tsráid, sa tsúil, while many prepositions prevent the t- being prefixed, e.g. ar an oileán, san uisce.