差很多 (크게 다르다)

Two fares can have very different prices

• A ticket costs 20 yuan and another costs 80 yuan. these这zhètwo两liǎngto open up张zhāngticket票piào(modifier / structural particle)的deprice价格jià géused in 参差差chà很多hěn duō presents their price gap as large.
• State the dimension: price, quality or another measure. used in 参差差chà很多hěn duō alone does not tell the listener which item costs more.

Name the things and the comparison dimension

• these这zhètwo两liǎng(measure word)个gesign牌子pái zi(modifier / structural particle)的deprice价格jià géused in 参差差chà很多hěn duō compares the prices of two brands. we / us我们wǒ menused in 伎俩俩liǎ(modifier / structural particle)的deway of thinking想法xiǎng fǎused in 参差差chà很多hěn duō compares two people’s ideas.
• about the same差不多chà bu duō can mean about the same in a comparison. Do not mechanically substitute it for used in 参差差chà很多hěn duō or confuse either expression with almost差点chà diǎn, nearly.

these这zhètwo两liǎng(measure word)个gediffer a lot差很多chà hěn duō。

Distinguish a difference from poor quality

• these这zhètwo两liǎng(measure word)个gegoods产品chǎn pǐn(modifier / structural particle)的dequality质量zhì liàngused in 参差差chà很多hěn duō says their qualities differ greatly. this这个zhè gegoods产品chǎn pǐn(modifier / structural particle)的dequality质量zhì liàngpoor in quality很差hěn chà evaluates one product as poor.
• A difference does not by itself identify the better product. poor in quality很差hěn chà and used in 参差差chà很多hěn duō make different claims.

Use numbers to make the gap checkable

• For 20 and 80 yuan, the absolute gap is 60 yuan. For 45 and 47 yuan, it is 2 yuan.
• Whether a gap counts as large depends on the task and scale. These examples provide the numbers instead of treating 很多hěn duō as an exact threshold.

Do not infer direction from the gap

• two两liǎnghome家jiā(modifier / structural particle)的deprice价格jià géused in 参差差chà很多hěn duō does not say which seller is cheaper. A clear account can add 第一家dì yī jiācheap便宜pián yi六十元liù shí yuán.
• A price comparison also does not prove a quality difference. Keep the measured dimension and direction explicit.

Make a useful comparison

• these这zhètwo两liǎngto open up张zhāngticket票piàoto part分别fēn biéto be / is是shì二十元èr shí yuánand / with和héeighty八十bā shícurrency unit (esp. Chinese…元yuán，price价格jià géused in 参差差chà六十元liù shí yuán gives both prices and an exact gap. price价格jià géused in 参差差chà很多hěn duō adds the speaker’s scale judgement.
• In a new example, name the pair, dimension, values and direction where relevant. Separate the numerical evidence from a judgement about how large it feels.

Read the full reference: HSK 5 grammar — Adverbs.