Conditional sentence: "I think it's about dopamine" This sentence starts with a conditional sentence structure, putting forward a theory, and then explains and supports it in the following text, demonstrating the clarity of the logical structure.
Compound sentence: By using conjunctions like "this is why" and "it's like", it constructs a compound sentence, showing clear connections between sentences, and increasing the complexity of the expression.
Reason adverbial clause: In the clause "as they need that fix all the time", the adverbial clause of reason introduced by "as" clearly explains the reason for the shopping addict's behavior, reflecting good logic and grammar usage.
Comparative: In the sentence "Shopping in small doses is fine though and makes the vast majority of people pretty happy", the comparative degree "pretty happy" is used appropriately, expressing the degree effectively and demonstrating flexible grammar usage.