Even though the English language is complex, dyslexic children CAN learn phonics! They need the support of a sequential, multisensory, structured reading program, and solid reading support at home (including reading together, playing games that isolate sounds or build words, etc.).
The Reading Rockets website focuses entirely on reading and how to help kids who struggle. See, for example, the section on strategies to help kids who struggle. Also check out this page for parents, which gives you tips on what you can do at home.
And here is a link to LD Online's collection of articles on dyslexia.