Hi Sofía!

Like is correct in all of these examples, and although it is possible to omit it and have good grammar, the meaning changes. 

In all of the above examples, 'like' is used to ask for a general description of something. So, "What was education like in the past?" means "Tell me in general about education in the past." 

It's not really possible to change it for another word without changing all of the sentence. "What is [x] like?" is a very common structure in English.  

We also use it for people, and the function is a little different. "What is Sofía like?" also asks for a general description, but only of personality. For appearance, we say "What does Sofía look like?"

Responses to these questions might be:

"What was education like in the past?" "Less people had the money for education, so classes had less students, and teachers didn't use marks like 7/10, etc."

"What is Lee like?" "He's a friendly person, but sometimes he is absentminded."

"What does Lee look like?" "He's tall, and he has dark brown hair and brown eyes."

Let me know if you have any other questions!

Best regards,

Lee

While English doesn't have any one governing body for regulation the way many of the Romance languages do, the instiution that reaches the farthest across the world is probably Cambridge. Their position, which has always seemed reasonable to me, is that any form of native English should be considered acceptable as long as it's used consistently on a word-to-word basis. This would mean that it's fine to write 'mom' and 'colour' in the same text, as long as you don't later use 'mum' and 'color.'  

As a private teacher in Spain I unfortunately often have to deal with the aftereffects of well-meaning teachers in primary/secondary schools who have told their students that this or that American spelling is outright wrong. Although there are certain advanced cases where you would want to adhere strictly to one national variant of English, I think making such criticisms is counterproductive unless dealing with very high level students. In the early stages of learning the language, when simply writing a text without major grammatical errors can be quite difficult, the last thing we want is to give learners the discouraging impression that the language is so full of landmines that an alternate spelling constitutes a mistake!

I think you're absolutely right to say there is only one English language in this sense. Discounting various creoles, the regional differences in English are minor compared to some other languages - they certainly pale in comparison to the regional variations you can see in Spanish, for example! So if an advanced student finds themselves in the situation where strict British or American English is required, the adjustments they need to make should be well within their ability. In any other situation, even if you considered this an error it would be difficult to justify making it a priority unless the student had mastered a great many other skills.

An 'icebreaker' is a speaking activity for the beginning of class, to help students relax and feel more comfortable speaking in the other language. They are normally ten minutes or less, and there are lots of examples available online. 

The important thing is just to focus on speaking and making students comfortable. Icebreakers are not for teaching new language or grammar- they may have one or two words of vocabulary but in general they should be easy and fun!

Best luck to your sister.

Regards,

Lee