2.pun: the clever or humorous use of a word that has more than one meaning, or of words that have different meanings but sound the same 双关语 ~ (on sth)
We're banking on them lending us the money─no pun intended! 我们正指望他们借给我们钱呢 bank 绝无双关之意!

3.Delighted: very pleased 高兴的;愉快的;快乐的 adjective ~ (to do sth) ~ (that…) ~ (by/at/with sth)
a delighted smile 愉快的微笑
I'd be absolutely delighted to come. 我非常乐意前来.
I was delighted that you could stay. 你能留下来我很高兴.
She was delighted by/at the news of the wedding. 听到婚礼的消息她很高兴.
I was delighted with my presents. 我对我收到的礼物很满意.

4.Credit: praise or approval because you are responsible for something good that has happened 赞扬;称赞;认可 uncountable ~ (for sth)
He's a player who rarely seems to get the credit he deserves. 他这个选手好像很少得到应得的赞扬.
I can't take all the credit for the show's success─it was a team effort. 演出成功不能都算成我一个人的功劳,这是集体努力的结果.
We did all the work and she gets all the credit! 工作都是我们干的,而功劳却都归了她!
Credit will be given in the exam for good spelling and grammar. 考试中拼写和语法出色者将受到表扬.
At least give him credit for trying(= praise him because he tried, even if he did not succeed). 至少该表扬他尝试过.