In this article, four Buryat complex constructions denoting alternatives and preferences (cf. Eng. rather than and instead of) are analyzed. Three of these are mono-finite (two are formed on the basis of the converb in -nxaar and one on the basis of a participle with the postposition orondo), one is bi-finite (with the dependent predicate in the optative introduced by a special form of the auxiliary verb of speech ge-). Their structural analysis is combined with a semantic analysis based on the following parameters: a) typical forms of the main predicate (the oppositions between indicative, imperative and irrealis forms);b) their effects: readings of the whole as a potential choice in the future (imperatives) or an unrealized choice in the past (indicative, irrealis), distribution of real / irreal interpretation between events of the main and dependent clause (e.g. the main clause in irrealis suggests the reality of the dependent clause event), and possible evaluative readings (likely positive evaluation of the main clause event in the case of the imperative, as something that is recommended, or of the dependent clause event in the case of the indicative);c) existence / absence of evaluative semantics on the construction level, their distribution between the clauses (e.g. the fixed negative evaluation of the dependent clause event with -nxaar, fixed positive evaluation of the dependent clause event with optative + ge- as compared to the evaluative neutrality of orondo);d) the character of the alternative, i. e. a concrete event compared with another such or with the social norm / expectation;e) possible lexical restrictions.