帮忙分析一下宾语从句

Think about how often it's used in our daily lives.这个句子中宾语从句谁引导的是how还是how ofen啊？想知道如果是how那么宾语从句是感叹句型吗？构成是什么啊？谢谢讲细点哦

how often 引导宾语从句
how的词组也都可以引导宾语从句
Please tell us how soon you will be ready .
Could you tell us how often you go abroad for a holiday ?
Could you tell us how long the meeting will last ?
I don’t know how far it is to the cinema .

宾语从句 【知识要点】 1.宾语从句在句中作及物动词或介词的宾语，从句放在主句之后，前后不用逗号分开。 2.引导宾语从句的词有： 连词that(在口语中that常可省略)，if, whether,如： he knows that jim will work hard. 连接代词who, whom, which等，如： do you know who (whom) they are waiting for? 连接副词when, where, how, why等，如：could you tell me how we can get to the station? 3.whether和if都有“是否”的意思，一般情况下两者可以换用，但在介词之后， 不定式之前，与or not连用，在句首或在引导表语从句，同位语从句时，只能用whether,如：i want to know if/whether the news is true. he doesn't know whether to stay or not? 4.宾语从句要用陈述句语序。 5.宾语从句一定要注意时态呼应，即：当主句谓语动词是过去式时，从句中谓语动 词也要用过去范畴的时态，但若从句陈述的是真理或客观规律，其谓语的时态仍用一般现在时，如： he asked who could answer the question. my father told me that the earth goes around the sun. 6.一个宾语从句只能用一个连词。 7.当主句谓语动词是think, believe等动词时，宾语从句的否定意义要放到主句中。另外，当主句主语为第一人称时，后面若接附加疑问句，那么附加疑问句的主语、谓语应与从句中的主谓语保持一致。如： i don't think he looks like his father, does he? 8.直接引语和间接引语也是宾语从句，直接引语是引述别人的原话，放在引号内， 不用连词联接；间接引语是用自己的话转述别人的话，通常用连接词与主句联接。 (1)陈述句变为以that引导的宾语从句，如： he said,“i'm happy.”[fy()[fy]]he said that he was happy. (2)一般疑问句变为if(whether)引导的宾语从句，如： he asked me,“does his father know mr green?” ---he asked me if his father knew mr green. (3)特殊疑问句变为由who, what, where, how等疑问词(连接代词或连接副词)引导的宾语从句，如： he asked me,“where is mr wang?” ---he asked me where mr wang was. 注意上述例句中连词、时态、语序等变化