I had flu for a couple of days.
1、我感冒了一兩天。
have flu 患流感，也可以說成: have the flu, catch a cold, have a cold
a couple of days （虛指）一兩天
2、發音技巧
for a couple of days 需要連讀/fɔ:rə/ / kʌpləv/
3、使用語境
Interpreter: I hear you've been ill.
翻譯：我聽說你病了。
Athlete: Well, I had flu for a couple of days, but I'm fine now.
運動員：嗯，我感冒了一兩天，不過現在好了。
這裡要特別注意的是well的用法。
well：
used to pause or give yourself time to think before saying something
嗯，這個〔用於停頓片刻或使自己在說話前有時間考慮〕