Breakdown of Учёный сосредоточился на том, что у этой теории есть странная особенность.
этот
this [f: эта, n: это]
на
on, at / by (transport) / to (a place) / to (in answer to)
у
at, by
есть
is, there is, to have
Questions & Answers about Учёный сосредоточился на том, что у этой теории есть странная особенность.
Why do we say на том, что instead of just на что?
The verb сосредоточиться (to focus) requires the preposition на plus the Prepositional case. In Russian, you cannot attach a что clause directly to a preposition. Instead, you must use a pointer word—the pronoun то in the matching case, which is the Prepositional том here—before что. It translates literally as 'focused on that, that...'
Why is the noun учёный (scientist) shaped exactly like an adjective?
Учёный is a substantivized adjective. This means it started as an adjective meaning 'learned' or 'scientific' but is now used as a noun, much like saying 'the rich' in English. Even though it acts as a noun, it still changes its endings exactly like a normal adjective would across all cases.
Is it normal to use the у ... есть structure for an inanimate object like теория?
Absolutely. While English distinguishes between people owning things and objects having features, Russian uses the у [Genitive] есть [Nominative] construction for both. Here, у этой теории есть literally means 'at this theory there is', which is the most natural way to say 'this theory has'.
How can I easily remember that особенность (feature) is feminine, since it ends in a soft sign?