There are problems for non-native English learners in both speaking and in listening that have to do with sentence stress and phrasing.
When a native speaker says a sentence, there is a pattern of stressed and non-stressed words. For example, let’s look at the sentence: “I left my keys at home.” The words that are stressed are “left,” “keys,” and “home.”
“I left my keys at home.”
In addition to stress, there is a pattern of phrasing, so a group of stressed and non-stressed words are slid together and pronounced as if they were one word. The above example would sound like:
“Ayeleft mykeys at’home.”
A non-native learning, who knows and understands the separate words “my” and “keys”, would be confused by what sounds like “mykeys.”
“Mykeys?” they would wonder. “What are ‘mykeys’? Do they mean ‘monkeys’? Is it a name? Is it a whole new vocabulary word?”
If non-native speakers don’t use stress and phrasing patterns when they speak English, they tend to pronounce each word in the sentence with equal stress. Everyone will understand what they are saying; it just sounds like they are a non-native English speaker.
In listening skills, knowing about stress and phrasing make a huge difference, the difference between understanding ” my” and “keys” and wondering what on earth are “mykeys.”
I’m going to list some guidelines for you to pay attention to. These are not “rules.” Americans are not taught this in schools. These are more descriptions of how people normally speak.
Words that are stressed are nouns, main verbs, adjectives, and adverbs. These are content words, the most important words in the sentence that give you the main meaning.
Unstressed words are articles, auxiliary verbs (except for can’t), pronouns, and prepositions. These are structure words that put the content words together. You can think of them as “small” words.
However, there might be a reason to emphasize a structure word, in which case the word is stressed. For example, if the question is:
“Whose keys did you leave at home?”
the answer would stress the word “my”
“I left my keys at home.”
If the question is: “Did Jane leave her keys at home?”
the answer would stress the word “I”
“No, I left my keys at home.”
In phrasing, related words are grouped together, for example, a noun with the associated article or possessive pronoun (“my keys”) or a preposition with its object (“at home”).
To help you learn to recognize stress and phrasing patterns, I suggest listening to native speakers. Get a recording that you can stop and replay. Listen to one sentence at a time and try to copy it. Pay attention to the stress and phrasing. Then won’t have to wonder what “mykeys” are.