CORRECTED SENTENCES:

These days, most of people have decided to migrate to city for their better life, but living in a big cities tend to have some problems.  = These days, most people have decided to migrate to cities to have better lives, but living in a big city can lead to some problems. 

In my opinion, governments could do much more to improve city life for the resident. = In my opinion, governments could do much more to improve city life for residents.

The main problem for anyone who hopes to migrate to big city is that the cost of living. = The main problem for anyone who hopes to migrate to a big city is the cost of living.

Those who live in the city have to pay much more than samll twon for housing, tranprt and even the food. = Those who live in the city have to pay much more than those who live in a small town for housing, transport and even the food.

Another issues is that urban city tend to suffer from high social problems such as crime and poverty. = Another issue is that an urban city tends to suffer from high social problems such as crime and poverty. / Another issue is that urban cities tend to suffer from high social problems such as crime and poverty. 

Futhermore, the quality of air is poor bue to the traffic also public tranprt and streets are always overcrowed. = Futhermore, the quality of air is poor due to traffic,  public transport, and the streets are always overcrowded.

As a result living in the city is always not good for people.

However, there are various of steps that government should do for resident to improve their quality of life.  = However, there are various steps that the government should do for residents to improve their quality of life. /  However, there are various steps that governments should do for residents to improve their quality of life.

Firstly, they could invest in social housing to reduce the cost of living.

Secondly, the politician has power to ban vehicles from city centre and promote the public transprt, which would help to reduce both air pollution and traffic congestion.  = Secondly, politicians have power to ban vehicles from the city centre and promote the public transport, which would help reduce both air pollution and traffic congestion. 

A third option would be to develop rural areas by moving industry and job creation.

In conclusion, although living in the city seem difficult compared to privincial, govenments could enhance resident's life by investing money and concerning our welfare. = In conclusion, although living in the city seems difficult compared to living in provinces, govenments could enhance residents' lives by investing money and concerning our welfare.