承接上一篇→英語句型結構(七)，本章進一步說明「頻率副詞」怎麼修飾句子呢？
正確答案: 頻率副詞顧名思義，用來敘述這個動作發生的頻率次數。
頻率副詞又分兩種，「大致的頻率」跟「明確的頻率」
若要描述「大致的頻率」，一般會放在句型結構「S + V + O + 地 + 時」的 V 之前後。
口訣：一般動詞之前，Be動詞之後。
若要描述「明確的頻率」，一般會放在句型結構「S + V + O + 地 + 時」的 時，位於句尾。
口訣：明確頻率看時間。
例句：
大致的頻率有：
always (100%), usually(80~90%), often (60~70%), sometimes (50%), seldom (30~40%), rarely (10~20%), never (0%)
一般動詞之前:
I always eat at home. (我總是在家吃飯) (100%)
You usually eat at home. (你/你們通常在家吃飯)(80~90%)
He often eats at home. (他時常在家吃飯)(60~70%)
She sometimes eats at home. (她有時在家吃飯) (50%)
It seldom eats at home. (牠不常在家吃飯)(30~40%)
We rarely eat at home. (我們很少在家吃飯)(10~20%)
They never eat at home. (他們從不在家吃飯)(0%)
—
Be動詞之後
I am always late. (我總是遲到)
You are usually late. (你/你們通常遲到)
He is often late. (他時常遲到)
She is sometime late. (她有時遲到)
It is seldom late. (牠不常遲到)
We are rarely late. (我們很少遲到)
They are never late. (他們從不遲到)
特定的頻率：次數 + 時間
次數:
once (一次), twice (兩次), three times (三次), four times (四次), five times (五次)…etc.
時間:
an hour (一小時), a day (一天), a week (一周), month (一個月), year (一年)
不論一般動詞或者Be動詞，都放在句尾:
I cook once a week. (我一周煮一次飯)
You cook twice a month. (你/你們一個月煮兩次飯)
He cooks three times a year. (他一年煮三次飯)
She cooks three times a day. (她一天煮三次飯)
He is late once a week. (他一周遲到一次)
We are late twice a month. (我們一個月遲到兩次)
They are late three times a year. (他們一年遲到三次)
問句則是用「How often」來詢問頻率。
Q: How often do you eat at home? (你多常在家吃飯?)
A: I always eat at home. (我總是在家吃飯) (100%)
A: I eat at home twice a day. (我一天在家吃兩次飯)
Q: How often are you late to school? (你多常上學遲到?)
A: I am always late to school. (我總是上學遲到) (100%)
A: I am late to school twice a week. (我一周上學遲到兩次)
頻率副詞的學問很深，以上先說明基本用法，之後再作補充。下一章介紹地方副詞。