Breakdown of Никто полностью не уверен в их сходстве.
не
not
в
in / to (direction)
их
their
никто
nobody
уверенный
sure
полностью
completely
сходство
resemblance
Questions & Answers about Никто полностью не уверен в их сходстве.
Why do we use the preposition в and the Prepositional case for "about their resemblance"?
In English, you are sure "about" or "of" something, but in Russian, the short-form adjective уверен requires the preposition в followed by the Prepositional case (literally "sure in"). That is why the neuter noun сходство changes to сходстве here.
Why is there a не before уверен if the sentence already starts with Никто?
Russian requires double negatives. When you use a negative word like Никто (nobody) or Никогда (never), you must also negate the main verb or predicate with не. Without the не, the sentence would be grammatically incorrect.
Could I use the long-form adjective уверенный instead of уверен here?
It would sound unnatural. When expressing a temporary state of mind, feeling, or attitude (like being sure, glad, or ready), Russian uses short-form adjectives as the predicate. The long form уверенный translates more closely to "confident" and is mostly used directly before a noun, as in уверенный человек (a confident person).
Why doesn't the possessive pronoun их change its ending to match the Prepositional case of сходстве?
Because их (their) is a third-person possessive pronoun. Unlike мой (my) or твой (your), the third-person possessives (его, её, их) are "frozen." They never change their form, no matter what case the noun they describe is in.
Learn Никто полностью не уверен в их сходстве and more in Russian
All course content and exercises are completely free — no paywalls, no trial periods, no signup needed.
- ✓ Practice with interactive exercises
- ✓ Track your progress with spaced repetition
- ✓Learn at your own pace — completely free