When you are learning English, you find it not clever to put an English sentence, word for word, into your own language. Take the sentence "How do you do?" as an example. If you look up each word in the dictionary, one at a time, what is your translation  ? It must be a wrong sentence in your own language. Languages do not just have different sounds, they are different in many ways. It's important to master  the rules  for word order   in the study of English, too. If the speaker puts words in a wrong order, the listener can't understand the speaker's sentence easily.Sometimes when the order of words in an English sentence is changed, the meaning of the sentence changes. But sometimes the order is changed, the meaning of the sentence doesn't change. Let's see the difference between the two sentences:"She only likes apples. " "Only she likes apples. " When you are learning English, you must use it as the English speaker does. The writer thinks it is  _  in learning English.
difficult to understand different sounds possible to remember the word order important to master the rules in different ways easy to master the rules for word order