I think something is missed.

youzou It doesn't make sense for me.

Right. The sentence should have been:
If you compact the trash, you will get a lot more space in the garbage can.

Prajwal

Thanks, I tough that it might be a sort of current English's idiom.

The sentence is correct. You will get a lot more trash in there. It is complete, grammatically correct and idiomatic.

I thought compact means compress, isn't it? Oh, I got it! You meant it means density of garbage will increase? But it doesn't make sense. I think in this case "a lot" is a little bit sententious. And compacting doesn't mean more garbage, it means compacted garbage with the same space has more space than not-compacted (! I have no proper adjective

youzouI thought compact means compress, isn't it? Oh, I got it! You meant it means density of garbage will increase? But it doesn't make sense. I think in this case "a lot" is a little bit sententious. And compacting doesn't mean more garbage, it means compacted garbage with the same space has more space than not-compacted (! I have no proper adjective ) one.

Well, I know the machine, but it doesn't mean that we have more garbage! I am no native English, are you sure it is one hundred percent OK? Please tell me exact meaning of "will get". I unconsciously thought that means you will have not you will have the possibility to have. Please enlighten me.

Yes, it is 100% OK.

I think I see your problem now. "To get" is a tricky, versatile verb. "To get something in (a space)" is to put it in the space by making it fit, e.g., I can only get one suitcase in the trunk of my Toyota.

Oh! thanks for your help.