e can divide English words into two groups, those containing a lot of information, and those having just a little information. Words with a lot of information are called content words, and words with only a little information are called function words. They usually have one syllable and a reduced vowel. Many have a reduced consonant. The reduction of the common function words makes sense, because they carry little information, and are often predictable.

Years ago, people needing to send a message quickly sent a telegram. Telegrams were expensive. Telegrams were paid for by the word, so eliminating unnecessary words saved money. A telegram could read:

I have spent all my money on wine and women. I am sleeping at a pig farm, and I am asking for your forgiveness. Is it OK for me to come home?

Or the telegram could be written in telegraph style:

Spent all money. Wine, women. Sleeping pig farm. Asking forgiveness. OK come home?

The saving is over 50%. All the words we deleted are function words. Only the content words remain. These are the words that receive stress. We could send another telegram, using only the function words, the unstressed words.

I have my on and. I am at a, and I am for your. Is it for me to?

This makes no sense. Notice that if we have the content words, we can guess many of the missing function words. If we can guess them, they have little information. The function word version is useless. It could mean just about anything, such as:

I have studied all my books on kindness and generosity. I am praying at a church, and I am asking for your happiness. Is it OK for me to send money?