hard and fast

hard 和 fast 的音标分别为 [hɑːd] 和 [fɑːst]。

hard 基本意思是“硬的，坚固的”，引申为“困难的；艰难的”，“努力地；猛烈地”等。fast 主要指“快速的，迅速的”，引申为“稳固的，可靠的”。

速记技巧：可以通过联想词根词义来记忆，hard 可以通过其形容词词性进行联想，表示“坚硬的”，而 fast 则可以通过其副词词性进行联想，表示“快速地”。同时，也可以通过对比记忆，将 hard 和 fast 两个单词的共同点和不同点进行比较，加深记忆。

Hard and fast这两个词源可以追溯到古英语，意为“坚硬的，固定的”。

变化形式：

1. 形容词形式hard 和 fast 都是比较常见的，此外，hard 还有副词形式hardly。

2. 名词形式有hardness 和fastness。

相关单词：

1. hardness n. 硬度；困难；坚决。例如：The metal has a high hardness.（这种金属硬度很高）。

2. fastness n. 快速；坚定；隐蔽。例如：The fortress is well protected and very fast.（这个堡垒保护得很好，非常快）。

3. hardly adv. 几乎不。例如：I can hardly believe it.（我几乎不能相信）。

4. haste n. 急速；匆忙。例如：Haste makes waste.（欲速则不达）。

5. fastidious adj. 挑剔的；小心的。例如：He is very fastidious about his appearance.（他对自己的外表非常挑剔）。

6. fasten vt. 固定；系牢。例如：Fasten your seat belt, please.（请系好安全带）。

7. adhere vi. 坚持；遵守。例如：He adheres to his principles even in difficult times.（即使在困难时期，他也坚持自己的原则）。

8. affirm vt. 断言；确认。例如：He affirmed that he had done nothing wrong.（他确认自己没有做错任何事）。

9. fix vt. 固定；安装。例如：He fixed a new bicycle tire.（他给新自行车轮胎打气）。

10. sturdy adj. 强壮的；坚固的。例如：The sturdy oak tree has stood the test of time.（这棵坚固的橡树经受住了时间的考验）。

常用短语：

1. hard and fast rule

2. hard and fast decision

3. hard and fast facts

4. hard and fast terms

5. hard and fast rule of thumb

6. hard and fast commitment

7. hard and fast deal

例句：

1. We need to make a hard and fast decision about whether to accept this job offer.

2. The contract includes hard and fast terms that we must comply with.

3. They made a hard and fast commitment to help us with the project.

英文小作文：

Time is a valuable resource that we all need to manage effectively. When it comes to making decisions, it is important to have a clear understanding of the hard and fast rules that apply to the situation. By doing so, we can avoid making mistakes or being taken advantage of by others.

In my opinion, it is essential to consider the consequences of our actions before making a decision. We need to weigh up the pros and cons of each option carefully, so that we can make the best choice for ourselves and our future. At the same time, we should also be aware of the potential risks and challenges that lie ahead, so that we can prepare ourselves accordingly.

By following these hard and fast rules, we can avoid wasting time on decisions that are not worth making, and instead focus on what really matters to us. This approach will help us to live a more fulfilling life and achieve our goals more effectively.