死ぬのではないかと恐れている。

to die; to pass away; to lose spirit; to lose vigor; to look dead; to cease; to stop

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

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

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

not; emphatic suffix

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

if; when; and; with; particle used for quoting (with speech, thoughts, etc.); quoting particle; promoted pawn; indicates question (sentence end)

to fear; to be afraid of