Gary is correct!

If your daughter is holding the shower head and some water accidentally gets on the glass, I would say "she splashes the glass". But if she deliberately points the shower head at the glass then I would say "she squirts water at the glass". "Squirts the glass" is not quite correct because it is the water that squirts, not the glass. Don't walk on the floor because it is wet. Literally, 'To light something up' means to shine a light on it. Metaphorically, you might say "when she smiles, her face lights up" Or, "I love her - she lights up my life". 'Ignite' is similar to "set fire to" but you wouldn't use it very often. When a rocket is launched into space, the rocket engines ignite. But you wouldn't ignite the engine in your car (you would light it) and you would not ignite a fire (you would light it -but you would not light it up) . But you might ignite a blow torch. So, 'ignite' has a sense of starting an explosion. She's soaking her feet in the water. Perfect. "I don't need any help thank you - I am quite able to do it myself". Or, "I am quite capable of doing this myself thank you." So, yes, the two words can sometimes be used interchangeably. If a member of staff is very efficient I might say "That person seems very capable". But if a child is very clever I would say "She is very able". So, in this example 'capable' has more of a sense of physical ability rather than mental ability. If you drink so much that you are unable to walk, the police can arrest you for being "drunk and incapable". "I am not able/unable to swim" means "I can't swim but I could learn" but "I am not capable of swimming" has the sense of "I can't swim and would never be able to learn" . It is somehow more definite.

How about: Does modern-day communication bring more exchanges between people? First of all we will talk about the evolution of social media, which allows better communication with each other, then we will see the contributions countries share with others, thanks to exchanges. "The social medias" is technically correct but simply "social media" is more common.

The problem with this text is that it is jargon - it is not intended for everyone to understand. I think it means the social world, as a contrast with the personal world. A similar contrast would be "the private and the public" or "the personal and the impersonal" . They are abbreviations for quite complex ideas. We could say "The social [world] involves meeting people, exchanging ideas etc". The personal [world] involves thinking, feeling etc." But the writer assumes that the reader knows these concepts so just says "The social" It is like 'artspeak' - the language that artists use to try to describe their work. It does not mean much to anyone except artists.

No, the sentence does not make sense in English.

A common example would be: Question:"Are you going to go to the concert?" Answer: "I might, but I have not decided yet". A more old-fashioned example. You are at a social event and don't know anyone. You might say to a group of people "Might I join you?" I am not going to answer the door at this time of night - you never know who it might be"