Student or Learner
are the following sentences wrong?
1. They have had a house built, a couple of years ago.
or They had had a house built a couple of years ago.
2. He ordered five trees to be sawn.
Will you please be so kind to correct my sentences, and give a explanation.
I believe you are trying to use the passive causative (e.g. get/have + something + past participle) in the first sentence.
Your first sentence should be:
1. They had a house built a couple of years ago
a. "had" is in the simple past because "a couple of years ago" is a specific time in the past
b. "had" + the house + "built" because it is passive causative (they asked and paid someone else to build the house for them; they didn't build it themselves)
c. you don't need a comma (,) before the time phrase
Your second sentence should be:
2. He ordered five trees (to) be cut down
a. "sawn" is not the past participle of "saw" and "cut down" is the correct verb in this context
b. "Order" can be used as a subjunctive verb, so the "to" in this case isn't necessary
Hope that helps