انا اللي بعرف It’s me who knows
Another post on a common expression. You’ll know the relative pronoun اللي (illi/@lli, and its variants يلي yalli and الـ l-), and if you don’t, you should read this post. The equivalent to ‘it’s X who Ys’ in English is expressed literally as X illi Y. Note that the verb (Y) agrees with the pronoun, whereas in English we usually use the third person form invariably. Note as well that the first vowel of illi/@lli is, like the vowel of the definite article, usually dropped following a vowel: ...