在英文句子中動詞必須在人稱及數量上與主詞一致

1. 單數主詞接單數動詞
   例如:
   He has a son.
   She is our teacher. 

2. 複數主詞接複數動詞
   例如:
   We have two kids.
   We are her students.

3. 不可數名詞視為單數
   例如: 
   A lot of milk is used in making this dish. (milk是不可數名詞)
   A lot of vegetables are used. (vegetable是可數名詞，且這裡是複數)

特殊狀況

4. 兩個單數主詞由 or, either/or, neither/nor連接時動詞用單數動詞，而兩個單數主詞若使用and連接則視為複數。
   例如:
   My aunt or my uncle is arriving by train today.
   My aunt and my uncle are arriving by train today.

5. 主詞若包含 either…or, neither…nor, not only....(but also)...時 動詞要和比較靠近的主詞一致
   例如:
   Either my sisters or Grandpa is going to the park.
   Either Grandpa or my sisters are going to the park.
   Neither she nor I am going to college.
   Not only my brothers but also my sister is taking the test.

6. 不定代名詞 each, anyone, everyone, someone, no one, anybody, everybody, somebody, nobody, something, anything, nothing 視為單數主詞，當主詞後面接的動詞要用單數動詞
   例如:
   Nobody is complaining.
   Everyone likes Peter.
   Something is wrong.

7. 不定代名詞 all, some 當主詞時，依其所指的名詞來判定為單或是複數
   例如:
   Some of the students were absent.  (some代表students中的一部分，故為複數)
   All of the furniture was broken. (all代表furniture中的全部，但furniture不可數故為單數)

8. 主詞後若有介系詞所形成的形容詞片語 ，動詞與原主詞一致。形容詞片語內的名詞數量不影響原主詞的數量。
   例如:
   The group of students is visiting Tainan.
   One of the most serious problems is lack of motivation.
   The books on the shelf are mine.

9. 有些單字看起來像單數其實是複數[集合名詞]，要接複數動詞
   如:
   The police are investigating the incident.

10. 有些s字尾的單字看起來像複數其實是單數，要接單數動詞
    如:
    The news is always bad nowadays.

11. 動名詞 (片語 )當主詞，動詞用單數動詞
    例如:
    Working with these students gives me a lot of pleasure.

1. children並非本句主詞，主詞是Linda故應使用單數動詞。
   How many children do Linda have? (X)
   How many children does Linda have?(O)

2. 主詞both(兩個都~)為數量代名詞，其代替的名詞應為可數複數，故應使用複數動詞。
   Both is qualified for the job.(X)
   Both are qualified for the job.(O)

3. 主詞sugar是不可數名詞，因此即使有some修飾數量，也應視為單數主詞。
   Some sugar are required for taste.(X)
   Some sugar is required for taste.(O)

4. 主詞為cookies中的大部分，由於cookies本身是可數複數，大部分most也應視為複數主詞。
   Most of the cookies was eaten.(X)
   Most of the cookies were eaten. (O)

5. 主詞為list(清單)，of items只是用來補充清單的內容為和(形容詞片語)，因此本句應視為單數主詞。
   The list of items are on the desk.(X)
   The list of items is on the desk. (O)

6. 主詞為either....or....所連接的兩個名稱，動詞應與相近的主詞Claire一致，故為單數主詞。
   Either Grace or Claire are helping today with stage decorations.(X)
   Either Grace or Claire is helping today with stage decorations. (O)

7. 兩個名詞由對等連接詞and相連，將形成複數主詞，故使用複數動詞。
   A car and a bike is my means of transportation.(X)
   A car and a bike are my means of transportation.(O)