A schwa is neutral, but it is not silent. By comparison, the silent E at the end of a word is a signal for pronunciation, but it is not pronounced itself: code is [kod]. The E tells you to say an [o]. If you leave the E off, you have cod, [käd]. The schwa, on the other hand, is neutral, but it is an actual sound, uh. For example, you could also write photography as phuh-tah-gruh-fee.
The schwa is a neutral sound, (no distinctive characteristics), but it is the most common sound in the English language. To make the uh sound, put your hand on your diaphragm and push until a grunt escapes. Don't move your jaw, tongue or lips, just allow the sound to flow past your vocal cords. It should sound like uh, not ah.
Once you master the two sounds [æ] and uh, you will have an easier time pronouncing 'can' and 'can't'. In a sentence, the simple positive 'can' sound like [k'n]. The simple negative 'can't' sounds like [kæn(t)].
|Positive||I can do it.||I k'n do it.|
|Negative||I can't do it.||I kæn(t) do it.|
|Extra Positive||I can do it.||I kææn do it.|
|Extra Negative||I can't do it.||I kænt do it.|