How do you make sentence by using as comfortable a pillow?

You can't make a sentence using "as comfortable a pillow" because it's not a complete thought. It's a phrase that compares the comfort of a pillow to something else.

Here are some examples of how to use the phrase in a sentence:

* "The feather pillow was as comfortable as a cloud." (This compares the pillow's comfort to a cloud.)

* "This new pillow is as comfortable as my old one." (This compares the comfort of the new pillow to the comfort of the old one.)

To create a full sentence, you need to add a subject and a verb:

* "The pillow felt as comfortable as a cloud." (This uses the phrase to describe the feeling of the pillow.)

* "I found this new pillow to be as comfortable as my old one." (This uses the phrase to explain the speaker's opinion of the pillow.)