I understand that the second sentence (it made me suffer a lot) is correct, but could anyone please explain why? I couldn't find an explanation on the internet. Many thanks.
All you have to do is crack open a good dictionary and note the way in which "to suffer" is used. As transitive verb, it means-- a) To experience or undergo something bad or painful (a heart attack, for example) Or b) To put up with; tolerate (a nuisance, a fool, etc.)
Note that in the sentence "It suffered me a lot" you're using "suffered" transitively that has "me" as its object. Thus you seem to imply that something ("it" here) tolerated you (because that's what "suffering" entails) and you were the reason behind their suffering. The first meaning of the verb given above doesn't really fit here because, well,you suffer losses, heart attacks, etc., and not people in that sense of the word. That's why you have to alter the sentence a bit and say instead-- "It made me suffer a lot." -- here it's clear that something is causing you to go through suffering.
Aside: Please note that there is another meaning of this verb in the transitive sense: To permit; allow. But that's not relevant to the question at hand.
Your question should be “Could anyone please explain why the first sentence is wrong?”
I assume that you trying to make “It suffered me a lot” mean “It caused me to suffer a lot” or “It was the cause of my suffering a lot” in which “it” is an event or an illness.
The answer is “English does not use the verb “to suffer” in that way.”
It is clearer if you substitute the subject “It” with a noun phrase:
*The broken leg suffered me a lot. (This would mean that the broken leg tolerated my being present a lot.")
The broken leg made me suffer a lot./ The broken leg caused me to suffer a lot / “The broken leg was the cause of my suffering a lot.”
To suffer is incapable of meaning “to cause to suffer.
Intransitive. “I suffered from a rare illness.” Here, “to suffer” = to experience or to undergo, with pain or inconvenience. The subject (“I”) does not instigate the action of the verb but is affected by the action of the verb.
Intransitive. “I suffered a rare illness”. As above but, here “a rare illness” is not the object but a complement. (Compare “He went [a distance of] five kilometres,” but *“[A distance of] five kilometres was gone by him.”)
Transitive: “I suffered him to borrow my car” Here, to suffer = to tolerate; to permit or allow (This use is now archaic.)