82. It's ages since I last saw him.

83. We started learning English four years ago.

84. Ly's father started smoking last year.

85. The editor last wrote to Mai a month ago.

86. How long ago did you start learning Spanish?

Here are the completed sentences based on your prompts:

82. I haven't seen him for ages.
- It's been a long time since I last saw him.

83. I have learned English for four years.
- We started learning English four years ago.

84. Ly's father started to stop smoking last year.
- Ly's father began to quit smoking last year.

85. The editor hasn't written to Mai for a month.
- The editor last wrote to Mai a month ago.

86. How long have you learned Spanish?
- How long ago did you start learning Spanish?

82. It's ages since I last saw him.

83. We started learning English four years ago.

84. Ly's father started smoking last year.

85. The editor last wrote to Mai a month ago.

86. How long ago did you start learning Spanish?