いったいぜんたい彼はどういうつもりなのか。

... the heck (e.g. "what the heck?"); ... in the world (e.g. "why in the world?"); ... on earth (e.g. "who on earth?")

he; him; his; boyfriend

topic marker particle; indicates contrast with another option (stated or unstated); adds emphasis

somehow; how; in what way; why; what kind of

intention; plan; conviction; belief

be; is; indicates past or completed action; indicates light imperative

indicates possessive; nominalizes verbs and adjectives; substitutes for "ga" in subordinate phrases; (at sentence-end, falling tone) indicates a confident conclusion; (at sentence-end) indicates emotional emphasis; (at sentence-end, rising tone) indicates question

indicates a question (sometimes rhetorical); or; whether or not; some- (e.g. something, someone); indicates doubt, uncertainty, etc.; emphatic prefix; suffix forming adjectives or adverbs; in that way