If I understand the rules of the vav hahipuch properly, which reverses the tense of a word from past to future or vice-versa, where the accent is placed plays a big role.
For example, the word אהבת means "you loved" (with the accent on the penultimate syllable, the letter ה). If you add a vav, and keep the accent where it was, it remains in the same tense. Meaning, ואהבת, with the accent on the ה, means "and you loved". However, if you move the accent to the end, where the accent is on the ת, then it means "and you shall love".
With this premise (please feel free to correct me), I'm finding some curiosities in parshas Terumah. There are a lot of verbs, all starting with a vav hahipuch. As I stated, the accent is all at the end. For example:
Exodus 25:14:
וְהֵֽבֵאתָ֤ אֶת־הַבַּדִּים֙ בַּטַּבָּעֹ֔ת עַ֖ל צַלְעֹ֣ת הָאָרֹ֑ן לָשֵׂ֥את אֶת־הָאָרֹ֖ן בָּהֶֽם׃
Which means, you shall bring.
Exodus 25:16:
וְנָתַתָּ֖ אֶל־הָאָרֹ֑ן אֵ֚ת הָעֵדֻ֔ת אֲשֶׁ֥ר אֶתֵּ֖ן אֵלֶֽיךָ׃
You shall place.
However, there are a lot of verbs, primarily ועשית, with the accent on the penultimate syllable. If we follow the rules I started with, that means they retain their past tense, even though there's a vav before it.
Some examples:
Exodus 25:11:
וְצִפִּיתָ֤ אֹתוֹ֙ זָהָ֣ב טָה֔וֹר מִבַּ֥יִת וּמִח֖וּץ תְּצַפֶּ֑נּוּ וְעָשִׂ֧יתָ עָלָ֛יו זֵ֥ר זָהָ֖ב סָבִֽיב׃
Notice וצפית has the accent at the end.
Exodus 25:12:
וְיָצַ֣קְתָּ לּ֗וֹ אַרְבַּע֙ טַבְּעֹ֣ת זָהָ֔ב וְנָ֣תַתָּ֔ה עַ֖ל אַרְבַּ֣ע פַּעֲמֹתָ֑יו וּשְׁתֵּ֣י טַבָּעֹ֗ת עַל־צַלְעוֹ֙ הָֽאֶחָ֔ת וּשְׁתֵּי֙ טַבָּעֹ֔ת עַל־צַלְע֖וֹ הַשֵּׁנִֽית׃
Exodus 25:13:
וְעָשִׂ֥יתָ בַדֵּ֖י עֲצֵ֣י שִׁטִּ֑ים וְצִפִּיתָ֥ אֹתָ֖ם זָהָֽב׃
Again, וצפית has the accent at the end.
Exodus 26:6:
וְעָשִׂ֕יתָ חֲמִשִּׁ֖ים קַרְסֵ֣י זָהָ֑ב וְחִבַּרְתָּ֨ אֶת־הַיְרִיעֹ֜ת אִשָּׁ֤ה אֶל־אֲחֹתָהּ֙ בַּקְּרָסִ֔ים וְהָיָ֥ה הַמִּשְׁכָּ֖ן אֶחָֽד׃
Notice וחברת has the accent at the end.
The examples are too numerous to list. What's the reason for this? Either grammatically, or if there's some deeper message here. I once asked a grammar expert and he wasn't sure, so we'll see what you guys come up with.