彼女が不誠実であるという事実は隠せない。

There's no disguising the fact that she is dishonest.

彼女(かのじょ)が不誠実(ふせいじつ)であるという事実(じじつ)は隠(かく)せない。

Kanojo ga fuseijitsu de aru toiu jijitsu wa kakusenai.

彼女 (かのじょ)

she; her; her; girlfriend; sweetheart

が (が)

indicates sentence subject (occasionally object); indicates possessive (esp. in literary expressions); but; however; still; and

不誠実 (ふせいじつ)

insincerity; dishonesty; untruthfulness; bad faith

だ (だ)

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

或 (ある)

a certain ...; some ...

と言う (という、とゆう)

called; named; as many as; as much as; all X; every X

事実 (じじつ)

fact; truth; reality

は (は)

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

Readings: ヒ、かれ、かの、か.の

Meanings: he, that, the

Readings: ジョ、ニョ、ニョウ、おんな、め

Meanings: woman, female

Readings: フ、ブ

Meanings: negative, non-, bad, ugly, clumsy

Readings: セイ、まこと

Meanings: sincerity, admonish, warn, prohibit, truth, fidelity

Readings: ジツ、シツ、み、みの.る、まこと、みの、みち.る

Meanings: reality, truth

Readings: ジ、ズ、こと、つか.う、つか.える

Meanings: matter, thing, fact, business, reason, possibly

Readings: イン、オン、かく.す、かく.し、かく.れる、かか.す、よ.る

Meanings: conceal, hide, cover