Could you tell me what you bought yesterday?是宾语从句么?

是!
以下是从网上找来的,供参考：
宾语从句
He sayshe is a boy．
She askedwhen she left．
宾语从句三步曲：
一．连接词
二．语序
三．时态：
一．连接词：
He has got a pen.I think…
I think ( that ) he has got a pen.
When does he study English? Lily asks…
Lily asks when he studies English.
Will you help me?I ask…
I ask if you will help me.
{
1--------(that)
2--------what when where why how
3--------whether if
二．语序：
“What is your name?” He asks me…
He asks me what my name is.
What did he buy yesterday? She asks…
She asks what he bought yesterday.
连接词＋主语＋谓语
三．时态：
当主句是一般过去时,从句要用过去的某一种时态．
Will he come?Jim asks…
Jim asks whether he will come.
Has he been abroad? I didn’t know…
I didn’t know if he had been abroad.