'I have eaten' is the present perfect tense of the verb 'to eat', 'I had eaten' is the past perfect and 'I will have eaten' is the future perfect.

I have eaten是动词eat的现在完成时；I had eaten是过去完成时；I will have eaten是将来完成时。

《牛津词典》

Happiness is not a point of future and not a moment from the past, but a mindset that can be designed into the present.

幸福不是未来的某个节点，也不是过去的某个时刻，而是能够融入到当下的一种心境。

youdao

I want to tell you about the past, present and future of the human population. So let's start with a few problems.

我想告诉你们有关人口数量的过去、现在和未来。那么让我们从一些问题入手。

youdao

Or patients might be advised to think less about the past and more about the present and the future.

VOA: special.2010.04.13

Israel's past and present and future generations form a collective entity, Israel, that collectively assents to the covenant.

犹太人的过去，现在，未来形成了一个共同的存在，全体犹太人都赞成这个契约。

耶鲁公开课 - 旧约导论课程节选

So, we are now going to do one standard problem where we will convince ourselves we can apply this formulas and predict the future given the present.

我们接下来将去研究一个标准问题,通过这个问题,我们能让自己相信,我们能利用这些式子,根据现状,预测未来

耶鲁公开课 - 基础物理课程节选

All of us are going to have to be pulling together and refocusing on the future and not just the present.

WHITEHOUSE: Discussing the Economy in Des Moines

The McGuinness retort is that other historic Irish figures had a past steeped in physical force republicanism and the Sinn Fein politician's candidacy in the Irish Presidential race is about the present and the future.

BBC: Selective memories of Martin McGuinness and Gusty Spence

These days, the past is increasingly less predictive, the future is almost unimaginable, and the present exists for about a nano-second.

FORBES: Leadership: Then and Now