think something out' think about it in detail .to prepare a plan or scheme. example: This is an interesting problem. I'll have to take some time and think it out. We spent all morning thinking out our plan. 'think something through to run over and try to settle something in one's mind. example : Let me think this through and call you in the morning. I will think through this matter and get back to you.

Can't answer this one since i never think before speaking :P

I will put the word "it" in for "something here because it's more naturally said / more common in normal speech - I hope that's okay. 1) I would like to think it out. (x) < awkward 2) I would like to think it over. (o) < Very common. "To think it over" means to consider all the possibilities and consequences of the issue/idea for a short (or sometimes a long) time before giving an answer or making a decision. 3) I would like to think it through. < Okay, but this is usually followed by... 4) I would like to think it through before I give you an answer. (or make a decision). < Correct. "To think it through" means to consider all the possibilities and consequences of the issue/idea for a short (or sometimes a long) time before giving an answer or making a decision. Ha ha. They mean the same thing.

If you think something out(=to a conclusion or result), you consider it carefully before making a decision. - I need some time to think things out. If some people say they can't argue something out(=to a conclusion or result), it means they cannnot reach any conclusion to it. The "out" functions as an adverb that means "to a conclusion or result", so "I'd like to think it out" sounds awkward. If you think something through, you consider it thoroughly(=in every part or way), together with all possible effects or consequences. - I didn't think through the consequences of refusing to take action. Don't be so obsessed with the "through", it's as simple as this. - I spent my summer vacation touring through(= various places in) France. - I'd like you to think through(=in every part or way) the consequences of refusing to take action.

Oops, I mean adverb.