I faced with these questions while I was doing exercise on translating.
- Does it have a correct structure: You have been working less lately.
- How much might it differ if I change the first one with the second sentence? And what about the "only's" position (for only or only for): Although he has been training this team for only half of a year, they've made great strides / He has been training this team for only half of a year (but) they've made great strides.
- Is it correct and should I use a preposition "a"?: They have been arguing for half an hour and I've lost any interest.