I tried catching the horse but without success Is this sentence correct? Why ?
It might be correct (depending on the context), but there's a subtle difference in meaning between the two forms.
The -ing construction usually implies:
- experimenting (Yesterday, I tried jogging to work for the first time)
- searching for or suggesting new solutions to a problem (If the charging icon doesn't show up on your phone, try using a different cable)
Therefore, your sentence would mean: I had this idea that catching the horse could work, but I tried it and it didn't.
The version with the infinitive does not have the above connotations, it would simply mean: I made an effort at catching the horse, but failed in the end.