明らかに誰かが嘘をついている。

明らか: clear, reveal, evident, obvious, apparent, obviously, uncover, plain, apparently
に: in, to, on, at, into, upon
誰か: someone, somebody, anyone, whoever
が: is, there, but, ga, will, however
嘘: lie, false, inappropriate, falsehood, falsehoods
を: o, the, to, wo
つい: about, just, quite, accidentally, eventually, inevitably, inadvertently, unconsciously, unintentionally
て: the, it, have
いる: are, to be, to stay, to have, necessary, to exist