Maybe you used to read the english words on book, but it is popular to read on phone for young people, I use this software "baicizhan"  every morning and can learn some new words daily,  this morning I know the word "signal" and the sentence is "when the traffic signal turns red, we should stop", you know the feeling is so wonderful since I pass the road everyday but never think ahout this sentence, maybe it drives me to learning english everyday, "surprise" is always the best return for learning english.