Learning how to correctly pronounce "purchase" is an important step in mastering English. To begin, the "pur" part of the word should be pronounced like the word "purr," as if you are a cat making a noise. The "chase" part of the word should be pronounced with a hard "ch" sound, like the word "cheese." The overall pronunciation should sound like "pur-chase." This is a two-syllable word with equal stress placed on each syllable.
When used in a sentence, the word is usually stressed on the first syllable. For example, "I need to purchase a new car." Here, the word "purchase" is emphasized when spoken. Likewise, the "chase" part of the word should be pronounced with the same force.
Finally, the emphasis on the "chase" part of the word should not be too strong. This is usually the biggest mistake that non-native English speakers make when saying the word. The emphasis should be on the "pur" part.
In summary, to correctly pronounce the word "purchase," say "pur-chase" with equal stress on each syllable and slightly more emphasis on the "pur" part.