I don't have enough money to buy a bike.

[keannu]

Can you replace enough with "much"? My grammar books only has the answer "enough", but I think much is also possible.

ex)I don't have enough money to buy a bike.

[Michael84]

Can you replace enough with "much"? My grammar books only has the answer "enough", but I think much is also possible.

ex)I don't have enough money to buy a bike.

not a teacher

Not without minor changes to the structure.

I don't have much money; therefore, I can't buy (/afford) a bike.

[keannu]

No. Enough means sufficient. Much means more than a little. Your sentence would read like this, "I don't have much money to buy a bike."
You could write, "I don't have much money, not enough to buy a bike."

It seems much just means "more" that's not comparable to the price of the bike, but it's still confusing, I don't get it perfectly. I'm sorry!

[keannu]

Much refers to the amount of money that one has or doesn't have, and is non-specific. (meaning it doesn't state how much money the person acutally has / $30, $50, $100, $1000 etc).

Whereas enough refers to the amount of money needed, in this case to purchase a bicycle and the price of the bicycle is a specific amount.

A specific amount is needed to purchase the bicycle, therefore much is grammatically wrong, because it is non-specific in this context.

For great esl and efl teaching materials check out www.Keh-english.com
or www.kiwi-english-house.com

Enjoy your teaching! Enjoy your learning!

I think much has the meaning of abundant, but as it doesn't indicate any degree related to "the money to buy a bike", enough fits better. I'm not completely out of confusion.