Bob watched TV last night.为什么不加s加ed?

Bob watched TV last night.为什么不加s加ed? 1.B ob watched tv at home last night.(对watched tv提问）（ ）（ ）BOb( )at home last night? Tom watched TV last year.(改为疑问句) My parents[ watched TV ]last night. i was watched TV last night.OR I watched TV last night.区别? Heken watched TV last night (对划线部分提问） 划线在：watched TV He watched a TV play last night.（对watched a TV play提问） 急 the boy watched tv last nigth 对划线部分进行提问、划线部分是watched TV Watched TV He watched TV last night.（陈述句变一般疑问句） I watched TV last weekend改为一般疑问句 We watched TV last night.改为否定句 We watched TV last nightlast night 是什么 成分 Mike watched TV last night改为一般疑问句 you watched TV last night,_____ _____?(反义疑问句) i s____ at home and watched TV last sunday. five,at,kids,last,watched,sunday,tv,home 重新排列 They watched TV last Monday evening改为否定句