the Fatwa Department Research Committee - chaired by Sheikh `Abd al-Wahhâb al-Turayrî
There is nothing wrong with a person writing with his or her left hand if that is easier for the person. The same goes for any other activity that requires a high degree of manual dexterity.
It is Sunnah to give preference to the right hand in all everyday clean actions that do not require any extra degree of manual dexterity, like putting on one's shoes and combing one's hair.
`A’ishah relates that the Prophet (peace be upon him) used to like to start with the right side when putting on his sandals, combing his hair, engaging in his ritual purifications, and in all of his activities. [Sahîh al-Bukhârî and Sahîh Muslim]
This, however, is a Sunnah and is not obligatory.
It is only obligatory for a Muslim to eat with his or her right hand. It is impermissible for the Muslim to eat with the left hand.
The Prophet (peace be upon him) saw a man eating with his left hand and ordered him to eat with his right hand. When the man said that that he could not do so, the Prophet (peace be upon him) said: “May you never do so.” From that time forward, the man lost the ability to raise his right hand. [Sahîh Muslim (2021)]
The Prophet (peace be upon him) told a boy who was eating with him to eat with his right hand.
If the child is left-handed, that is perfectly alright. The child can write with his or her left hand without any problem. It is unnecessary to insist upon the child writing with his or her right hand or using the right hand when engaging in other activities requiring an extra degree of manual dexterity.
Forcing a left-handed child to use his or her right hand for such activities can have detrimental consequences for the child's confidence, education, and self-esteem.
And Allah knows best.
Source: Islam Today