Use of を and に with 頼る (to depend on)

Question

Why is the direct object taking を in (1) and に in (2)? What are basic rules that drive these two sentence constructions?

(1) 叔母は父を頼っている
'My aunt is counting on my father's help.'

(2) 農民は収入を[牧羊]{ぼくよう}に頼っていた
'The farmers depended on sheep-farming as their source of income.'

I am not sure of the technical terms but there is clearly a bit more going in (2). However the farmers in (2) are relying on sheep farming in the same way that my aunt is relying on my father in (1).

I think (1) could be amended as (3) to comply with the same grammatical rules as (2):

(3) 叔母は援助を父に頼っている
'My aunt is counting on my father for support.'

but I still do not understand how/when/what grammatical rules are being used.

Answer 1

The role of 父 in (1) and 牧羊 in (2) are not the same. 父 has volition, and can be an agent of some helping activity on its own will, whereas 牧羊 is something to happen. In fact, you cannot have 牧羊 in the position of the を-phrase in (1).

* 農民は牧羊を頼っていた

Also, (3) is actually ungrammatical. in order to express the intended meaning, you have to say

叔母は(父の)援助に収入を頼っている

Conclusion is that, 頼る has two different constructions with different meanings:

• AがBを頼る "A relies on B's activity"
• AがCにDを頼る "A relies on event C for D"

The fact that they are different can be made clear by the fact that the former meaning can be expressed by the predicate 頼りにする, but the latter cannot.

叔母は父を頼りにしている
* 農民は牧羊を頼りにしている