for free

for free的音标是[fɔː(r) freɪ]，意思是免费。记忆技巧是：for表示“为了”，free表示“免费的”，合在一起就是“为了自由（免费用）”的意思。

以下是我为您列举的英文词源、变化形式和相关单词，以及不少于100字的解释：

1. "for" - 这个词来自拉丁语"ad"，意为"到，向"，"for free"就是"免费地"的意思。

变化形式："free"本身是形容词和副词，表示"免费的，自由地"。

相关单词：

"freedom" - 自由，源自拉丁语"liberty"，意为"无约束"。

"freelance" - 自由职业者，源自拉丁语"liber"，意为"自由的"。

"frequent" - 频繁的，源自拉丁语"frequens"，意为"经常发生的"。

"freeze" - 冻结，来自古英语"frecan"，意为"凝固"。

"freight" - 货物，来自古英语"frec"，意为“装载”。

"freewheel" - 空转，自由行驶，来自古英语"frecwealh"，意为“自由旋转”。

"freely" - 自由地，无拘无束地，来自拉丁语和古英语的形容词形式。

"freeride" - 自由骑行，来自英语单词“free”和“ride”，表示自由骑乘。

"freewill" - 自愿的，来自拉丁语“liberty”，表示自由意志。

以上这些单词都与“free”这个词源有关，表示免费、自由、频繁、自由行动、自由选择等含义。这些单词在英语中广泛应用，反映了英语词汇的丰富性和多样性。

常用短语：

1. for free 免费

例句：You can download this software for free from our website.

2. in for it 自找倒霉

例句：He knew he was in for it when he agreed to do the job.

3. for all 无论如何

例句：For all his efforts, he still failed to win the competition.

4. in for a rough time 将要遭受艰难的处境

例句：He knew he was in for a rough time when he took on the job.

5. for all that 尽管如此

例句：For all that, she still managed to finish the race.

6. in for it 自找麻烦

例句：He knew he was in for it when he agreed to help them.

7. for good 永久地

例句：They decided to get married for good.

英文小作文：

I am a passionate person who loves to explore new things and try new experiences. One of my favorite ways to do this is by traveling. However, traveling can be expensive, especially if you want to go somewhere exotic or far away. Fortunately, there are many places that you can go for free or at a very low cost. One of my favorite places is the local park. It"s a great way to get some fresh air, exercise, and meet new people. I also enjoy volunteering at local organizations or charities because it"s a great way to give back to the community and make new friends. In conclusion, there are many ways to explore the world without spending a lot of money. It"s important to be open-minded and adventurous, and take advantage of these opportunities whenever they arise.