What is the difference between Acquire and gain and obtain and get ?Feel free to just provide example sentences.

Acquire: Most often used in the context of obtaining something of value (or some knowledge/skill of value). It's typically used in the context of obtaining something that is highly valued or difficult to get, like a famous painting or the ability to speak another language.

Gain: Most often used in the context of obtaining more of something than you already have. For example: "he gained more weight last month". So it's typically used when expressing relative increases in an amount. It can also be used in the context of 'gaining entry' into somewhere which basically means to get inside somewhere that was locked or secured in some way.

Obtain: This word can be used whenever you come into possession of something or some knowledge which you previously did not have. It's most often used in reference to physical things, but it can also be used in reference to non-physical things. Compared to get, obtain sounds a little more formal and often suggests there was time or effort involved in getting something.

Get: This is probably the most generic of all these words. It can be used any time you come into possession of something or some piece of knowledge which you previously did not have regardless of the value and regardless of how much time/effort it took. Compared to obtain, it's more casual and informal.