Breakdown of Ему некогда врать, поэтому я сомневаюсь, чтобы он тебе соврал.
он
he / it (for a masculine noun) / it (for a neuter noun)
я
I
ты
you (singular)
поэтому
so (therefore)
Questions & Answers about Ему некогда врать, поэтому я сомневаюсь, чтобы он тебе соврал.
Why do we use чтобы here instead of что?
After verbs of doubt like сомневаться or verbs of denial, Russian often uses a subjunctive clause introduced by чтобы instead of что. This emphasizes the unreality or improbability of the action, showing you think it is highly unlikely that he lied.
Why is соврал in the past tense if I am doubting something right now?
In Russian, the subjunctive mood is always formed using the past tense. Because чтобы triggers the subjunctive in this sentence, the verb following it must be in its past tense form (соврал), regardless of when the actual doubting is happening.
Why does the sentence use the imperfective врать first, but the perfective соврал later?
Врать is imperfective because it refers to the general activity of lying; he has no time for lying in general. Соврал is perfective because it refers to a specific, single, hypothetical event: the specific act of him telling a lie to you.
Why does the sentence start with Ему некогда rather than У него нет времени?
Некогда is an impersonal predicative adverb meaning 'there is no time', and like many impersonal words, it requires the logical subject to be in the dative case (Ему). It is a very natural and concise way to say someone is too busy to do something.