Hello to the Hebrew speakers and to all those interested!

I have two questions related to the pronunciation of certain Hebrew words.
1. What is the first vowel in the past tense form, 3rd person singular feminime and 3rd person plural of the pa'al verbs? (סָגְרָה, סָגְרוּ / לָמְדָה, לָמְדוּ) Is it a קָמָץ קָטָן or a קָמָץ גָדוֹל? According to my knowledge and my calculations, it should be a קָמָץ קָטָן, but I constantly find this words transliterated as [sagra, sagru / lamda, lamdu], so with a קָמָץ גָדוֹל.
2. What is the correct pronunciation of צִוּוּי (the imperative mode)? Is that a double vav, as in אוויר? In such case, what is the dagesh doing there?
Thank you very much for your assistance.
