After the government has introduced tougher sentences

[Bassim]

I am not sure if my sentence sounds natural. Would you please correct my mistakes?

After the government has introduced tougher sentences for minor crimes, there was also a large drop of reported serous crimes.

 

[GoesStation]

The first clause should use the simple past. "Also" doesn't belong in the second clause unless a previous sentence discussed something to which this one adds more information.

 

[Bassim]

I will repeat my sentence after GoesStation's corrections as an exercise and to remember it if I should write a similar sentence.

After the government introduced tougher sentences for minor crimes, there was a large drop of reported serious crimes.

 

[emsr2d2]

I will repeat my sentence after GoesStation's corrections as an exercise and to remember it if I should write a similar sentence.

After the government introduced tougher sentences for minor crimes, there was a large drop [STRIKE]of[/STRIKE] in reported serious crimes.

See above. I'd use "a big drop" (though "large" isn't wrong) and I'd probably use "crime" at the end. There's something a little clunky, though I can't put my finger on it, about "in reported serious crime". I might use "a big drop in the number of serious crimes reported". Note that, in that construction, the plural "crimes" would be necessary.