faithful的音標是[?fe?θfl]，翻譯成中文是忠誠的，真摯的。速記技巧是：fei信夫。

faithful這個詞的詞源可以追溯到拉丁語詞匯“fidus”，意思是“信任”或“忠誠”。faithful這個詞本身在英語中已經發生了許多變化形式，包括其名詞形式“faithfulness”，形容詞形式“faithful”，以及副詞形式“faithfully”。

相關單詞：

“trust”和“believe”都與faithful有相似的含義，都表示對某人的信任或忠誠。

“loyal”表示忠誠，其詞源也與拉丁語有關。

“credible”表示可以信賴的，其詞源可以追溯到拉丁語的“credo”，意為“我相信”。

“faith”本身也是faithful的一個相關單詞，表示信仰或信念。

“faithfully”是faithful的副詞形式，表示忠誠地、真誠地，在寫作和文學中經常使用。

faithful這個詞在英語中也被用作形容詞，表示忠誠的、真誠的或可靠的。它的使用可以表達對某人或某事的信任和忠誠。例如，“He is a faithful friend”就可以被理解為“他是一個忠誠的朋友”。這個詞在表達誠實和守信用的品質時非常常用。

常用短語：

1. be faithful to (someone)

2. be faithful in (something)

3. faithfully

4. be true to

5. be loyal to

6. be steadfast in

7. be consistent with

例句：

1. I am faithful to my friend in keeping our promises.

2. She is faithful in her work, always putting in a full day"s effort.

3. Our friendship is based on mutual trust and faithfulness.

4. He is true to his word and always keeps his promises.

5. She is loyal to her family and always stands by them in times of need.

6. The two countries are steadfast in their support of each other"s interests.

7. The new policy must be consistent with our original objectives.

英文小作文：

My Faithful Friend

I have a faithful friend who always stands by me in times of trouble and joy. We have shared many experiences together, from happy moments to difficult challenges. She is always there for me, no matter what happens, and I am grateful for her unwavering support and loyalty. She is my rock, my confidante, and my best friend. I am blessed to have such a faithful friend in my life.