deal with a heavy hand
'Tratar con mano dura' is a Spanish phrase that literally translates to 'to treat with a hard hand' in English. However, this phrase is used idiomatically and doesn't often refer to physically using a hard hand. Instead, it is frequently used to describe a stern or harsh approach to dealing with a situation or person. An analogous expression in English might be 'to take a hard line' or 'to crack down' on something.
Teachers must deal harshly with the problem of bullying.
The phrase shows the use of 'tratar con mano dura' in a context where educators are required to adopt a strict approach towards a serious issue such as school bullying.
To ensure safety, it's necessary to deal harshly with criminals.
In this sentence, 'tratar con mano dura' is used to convey the idea of stringent measures that must be taken to tackle crime, directly indicating that criminals should be dealt with firmly.
Parents sometimes have to deal harshly with their children's misconduct.
In this context, 'tratar con mano dura' refers to parents needing to adopt a strict attitude or approach when handling cases of poor behaviour exhibited by their children.