比较精简的日常说法：我昨天看到（我的）老师在超市里买水果（了）。 括号内的是可以省略的，希望对你有用。

time: 昨天 place: 在超市里 subject: 我 昨天 我 在超市里 = 我 昨天 在超市里 = 昨天 在超市里 我 normally we put the time before the place. and we can put the subject anywhere. 我看到我的老师在买水果 ----- this phrase highlights that the moment(so we must use 在 here) ---- when i saw my teacher, he was buying fruit. ---- u see, we say: 买水果 instead of 买些水果, because we just want to express the action --- buying, we dont care which fruit did he buy. 我看到我的老师买了些水果 ----- this phrase highlights that the result ---- i saw that my teacher had bought some fruits. ---- here, we add 些----some, because we highlight the result ---- he bought some fruits. 我看到我的老师把水果买了 ----- “把字句” highlights more the result of the action. normally for this example, we just use these two kinds of phrases above. if we use 把字句 here, we need some situation: for example, - "hi, have ur teacher bought fruit? because he promised me that he would buy some fruits." - "oh yeah, 昨天我在超市看到我的老师（已经）把水果买了。" we use 把 to highlight that the teacher didnt forget to buy some fruits. so remember this: “把字句” highlights the result of the action. for example: I killed him. 我杀了他。 ----- this is a state. 我把他杀了。 ----- we put the verb "kill" at the end of the phrase because we want to highlight the "kill". we can do this: 我已经把他........ we say like this, we dont say the verb on purpose, so the listener gonna have a huge curiosity to know what happened. obviously, we cant do this without the 把字句.

This is my understanding from your Mandarin sentences. You can take these as a reference to distinguish their differences. 昨天我在超市里看到我的老师买了水果。:Yesterday I saw my teacher bought fruit at the supermarket. 昨天在超市里我看了我的老师在买水果了。Yesterday I saw my teacher was buying fruit at the supermarket. 我昨天在超市里看到我的老师把水果买了。:Yesterday I saw my teacher bought fruit at the supermarket. Notice: The last Mandarin sentence is a little strange and not natural at all. Or 我昨天在超市里看到我的老师把水果买走了。 Or 我昨天在超市里看到水果被我的老师买走了。(Yesterday I saw fruit bought by my teacher at the supermarket.) Just for reference. If you still have any question, feel free to contact me.

都可以用， 第一句：昨天我在超市里看到我的老师买了水果。三句里面最自然 第二句：昨天在超市里我看了我的老师在买水果了 中间的“在”应该去掉比较好

昨天，我在超市里看到我的老师买水果。 昨天在超市里我看到我的老师在买水果。 最后那个别扭。