Looking up...
To make a firm decision to purchase something.
经过考虑，他决定要买那辆二手车。
After consideration, he decided to buy that used car.
她决定要买一台新电脑，因为旧的太慢了。
She decided to buy a new computer because the old one was too slow.
Commonly used in daily conversation to express a decision about purchasing. Often implies the decision is final or well-considered.
The phrase follows the structure '决定 + 要 + verb' to express a decision about an action. Similar patterns include '决定要去' (decided to go) or '决定要学' (decided to learn).
The phrase '决定要买' implies a decision has been made, but the actual purchase may or may not have occurred yet. For completed purchases, use '已经决定买了' (already decided to buy) or '买了' (bought).
组合词：'决定' (juédìng, to decide) + '要' (yào, to want/need) + '买' (mǎi, to buy). '决定' comes from classical Chinese, while '要买' reflects modern Mandarin usage emphasizing intent.
This phrase is straightforward and literal. It is often used in contexts where the speaker has weighed options and reached a conclusion about purchasing. It can be used in both spoken and written Chinese.