Translation:If I had to do it, I would do it in eight years.
"Se eu tivesse QUE fazer isso, eu faria em oito anos." is correct too.
If I had to do it, I would take 8 years (to do it). This is very common when saying how long it would take to complete a task. But I was marked wrong.
However, this could mean 'If I had to do it, I would begin in 8 years' In English too, so I am a little confused here.. Help?
DL's sentence could be expressed with less redundancy:
If I had to do it, it would take [me] eight years.
I think the second is more accurate here. I thought of it as if two women were discussing having children and one said, 'If I had to do it (have children), I would do it in eight years'. This can consequently be put into many other situations, as well, such as job changes and the like, though it seems like an awful long time!
Does this mean that I'll start the task in eight year's time, or that the task itself will take me eight years to complete?
eu o faria, yes. ( or eu fá-lo-ia, writen language) - you cannot put unstressed pronouns after verbs in the future tenses.
In spanish we can say "tener que" instead of "necesitar" -- this is the first I'm seeing "ter que" instead of "precisar" for portuguese. Is this use always acceptable, or are there only particular instances where you can say "ter que"? Obrigado! :)
Both clauses need an object after the transitive verb "do".
If I had to do it, I would do it in eight years.
I live in the UK. I am 54. My suggestion is above is valid, I believe. US English may suggest otherwise to you, which is fine, of course.
A transitive verb requires an object in standard English, whatever variant you speak. If you prefer not to use the pronoun "it", this is another valid alternative which functions as an object:
If I had to do it, I would do so in eight years.