If unsure about ie or ei, if the audio of the vowel is as In short /i:/, we spell it ie; but after the letter c, we spell it ei: It really works a bit much like the DSL splitter in your house, separating voice frequencies from data frequencies, although https://cristiangfcxt.ageeksblog.com/26313060/top-spelling-rules-for-ssc-cgl-secrets