Why is を used in this situation? 私は先生がネコを好きだと思います


私は先生がネコを好きだと思います

Why を and not が twice?




This is an interesting phenomenon. In a simpler sentence:

> 先生が猫が好きだ,

the predicate `好き` is a na-adjective, so it does not have the ability to
assign accusative case to its arguments. Therefore,

> ×先生が猫を好きだ

is ungrammatical. However, when it is embedded under a verb that can assign
accusative case and there is no other noun phrase that needs to be assigned
accusative case, then the object of `好き` can receive accusative case
(remotely) from that verb. Either the nominative (`が`) or the accusative (`を`)
becomes available.

> 私は[先生が猫{が/を}好きだ]と思います

In the example above, `猫` receives accusative case `を` not from its predicate
`好き` but from the verb `思う`. This is called **Exceptional Case Marking
construction**.

Similarly in English, the subject in a simple sentence needs to be in
nominative case:

> He is smart.

so having accusative case on the subject is ungrammatical:

> ×Him (is/to be) smart

However, when it is embedded under a verb that can assign accusative case and
there is no other noun phrase that needs accusative case, then the embedded
subject can receive the accusative case (remotely) from the verb in the main
clause:

> I consider [him (to be) smart].

Here, `him` is accusative case marked not by its predicate `smart` but by the
verb `consider`.




This is an interesting phenomenon. In a simpler sentence:

> 先生が猫が好きだ,

the predicate `好き` is a na-adjective, so it does not have the ability to
assign accusative case to its arguments. Therefore,

> ×先生が猫を好きだ

is ungrammatical. However, when it is embedded under a verb that can assign
accusative case and there is no other noun phrase that needs to be assigned
accusative case, then the object of `好き` can receive accusative case
(remotely) from that verb. Either the nominative (`が`) or the accusative (`を`)
becomes available.

> 私は[先生が猫{が/を}好きだ]と思います

In the example above, `猫` receives accusative case `を` not from its predicate
`好き` but from the verb `思う`. This is called **Exceptional Case Marking
construction**.

Similarly in English, the subject in a simple sentence needs to be in
nominative case:

> He is smart.

so having accusative case on the subject is ungrammatical:

> ×Him (is/to be) smart

However, when it is embedded under a verb that can assign accusative case and
there is no other noun phrase that needs accusative case, then the embedded
subject can receive the accusative case (remotely) from the verb in the main
clause:

> I consider [him (to be) smart].

Here, `him` is accusative case marked not by its predicate `smart` but by the
verb `consider`.

