Different between 力強い with 強力


I found an interesting word in a box kind of stamina drugs which said 力強い
(chikaradzuyoi) which means powerful. The interesting thing for me is, I
noticed the word may be interchangeable, like with 強力 (kyouryoku) which means
powerful too, and I mostly use 「強力」rather than「力強い」. Is this a colloquial
matter? Or nuance?




> stamina drugs which said 力強い (chikaradzuyoi) which mean powerful.  
>  I notice the word in interchangeable way, like 強力 (kyouryoku) which mean
> powerful too, and I mostly use 「強力」rather than「力強い」. Are this colloquial
> matters? or nuance?

It's normally 強力 that we use for the strength of a drug.  
力強い for 強壮剤{きょうそうざい} is an unusual expression, and so it's almost funny but
ambiguous. It's successful for getting the customers' attention.

力強い is more explanatory to me, it's to describe a **_manner_** of something or
someone or a scene.

> デジタル大辞泉 says **きょうりょく【強力】** is
> 力や作用{さよう}が強いこと。また、そのさま。ごうりき：「強力な味方{みかた}」「運動{うんどう}を強力に推進{すいしん}する」

You can say 力強い味方, and maybe also 運動を力強く推進する. We say a work of art is 力強い, but
強力 doesn't work for it.

> **ちからづよい【力強い】**  
>  **１** いかにも力がありそうに見えるさま。力がこもっていて頼もしく感じられるさま。「―・い横綱の土俵入り」「―・い演説」  
>  **２** たよりになるさま。安心できるさま。気強い。「彼に来てもらえば―・い」  
>  （デジタル大辞泉）




> stamina drugs which said 力強い (chikaradzuyoi) which mean powerful.  
>  I notice the word in interchangeable way, like 強力 (kyouryoku) which mean
> powerful too, and I mostly use 「強力」rather than「力強い」. Are this colloquial
> matters? or nuance?

It's normally 強力 that we use for the strength of a drug.  
力強い for 強壮剤{きょうそうざい} is an unusual expression, and so it's almost funny but
ambiguous. It's successful for getting the customers' attention.

力強い is more explanatory to me, it's to describe a **_manner_** of something or
someone or a scene.

> デジタル大辞泉 says **きょうりょく【強力】** is
> 力や作用{さよう}が強いこと。また、そのさま。ごうりき：「強力な味方{みかた}」「運動{うんどう}を強力に推進{すいしん}する」

You can say 力強い味方, and maybe also 運動を力強く推進する. We say a work of art is 力強い, but
強力 doesn't work for it.

> **ちからづよい【力強い】**  
>  **１** いかにも力がありそうに見えるさま。力がこもっていて頼もしく感じられるさま。「―・い横綱の土俵入り」「―・い演説」  
>  **２** たよりになるさま。安心できるさま。気強い。「彼に来てもらえば―・い」  
>  （デジタル大辞泉）

