<p>Actually, now that I look at the original post, and not gle’s post #16, I believe that “would become” could be used for either the (simple) present or (simple) future, subjunctive in either instance.</p>
<p>(I thought he was talking about “would have become.”)</p>
<p>Also I should acknowledge that silverturtle is correct: “Would have become” can be used in the past (perfect) subjunctive/conditional:</p>
<p>For example: “If I had known about the opportunity to go to Mars, I would have become an astronaut.”</p>
<p>The first verb (“had known”) is past perfect subjunctive, and the second “would have become” is past perfect subjunctive/conditional.</p>
<p>Thanks for the clarification.</p>
<p>You’re welcome, silverturtle. It has occurred to me that some grammarians might distinguish the conditional from the subjunctive in English usage, although these moods are identical in Latin (to the best of my knowledge). The reason for this is that one cannot say, “If I would have known about the opportunity to go to Mars, I would have become an astronaut.” The first clause takes “had known” only, so the forms are not genuinely interchangeable.</p>