When do we do things "over"?

In this lesson (and also in some other lessons) I’ve noticed several phrases with “over”: “switch over”, “copy over” and so on, maybe “transfer over”. Is the word “over” really necessary here? The sentences are fully understandable without it. If I forget to use “over” in a similar sentence of my writing, will it be a mistake, or unnatural usage, or completely acceptable?

All members of TheLinguist will have to switch over to LingQ at some point. For the purposes of testing the new system and getting feedback, we hope many of you will switch over now.

However, we will copy over all your words and phrases to the new system and you will be able to do all your reading, listening and vocabulary activities on the LingQ site.

As you are using “over” in your examples it is a preposition. Maybe this definition and example will make mover sense:

From one position or state to another.

Please pass that over to me.
He came over to our way of thinking on the new project.
Come over and play!
I'll bring over a pizza.

So, over is necessary in these examples to show that someone or something is going from one position to another.

In some sentences there will be no difference whether over is used or not. For example
“Pass the ball to me” versus “Pass the ball over to me”

Hopefully someone else can provide a more clear answer, but that’s the best I can do at the moment.

Thank you. Although it is not absolutely clear for me, I’ll try not to forget to add “over” in similar phrases when it obviously changes the meaning. When it doesn’t change anything and I don’t forget that “over” can be added in that situation, I’ll try to add it and see the reaction of a person who is reading or listening to me.

Switch to , switch over to, no difference. Copy , copy over, no difference. In both cases, the over is redundant.

Come to my house, come over to my house, no difference but the second one is friendlier.

I humbly recommend that you do not expect things in a foreign language to be absolutely clear. The gradually get clearer.

I think that the last two sentences from Steve are a very useful recommendation to the beginner to intermediate learners like me. There are quite a few occasions that I cannot understand the logic or the usage of the target language, however I usually get used to it over time and can accept it. I gradually get less frustrated. Of course, the answers from native speakers to the questions from non-native speakers are often useful for me to understand the language. I think that this forum is very useful.

Thank you Steve.

Of course I have been following your advice already. I ask not more than a few percent of questions I have. With other questions I usually wait until this word or expression occurs in other lessons several times, and I ask a question only if even after that I can’t figure out its meaning with confidence.

I’ll try to ask less questions and search for more examples.