Terima kasih → Thank you (Formal)
Terima kasih is the standard, polite way to say “thank you” in Indonesian. It gives off a sense of formality, and so you will come across this phrase often when listening to news broadcasters, people in the service industry, or... ATM machines. People in closer friendships/relationships typically don't use this phrase amongst one another.
Terima kasih banyak → Thank you so much (Formal)
Banyak in this context means “many”. So terima kasih banyak essentially means, “Thank you so much”.
Makasih → Thank you (Informal)
Makasih is the abbreviated, informal version of Terima kasih and this is the phrase that is more commonly used amongst friends and people who are familiar with one another.
Trims → Thank you (in texting)
There are a lot of abbreviated phrases in Indonesian that are used when texting or casual emailing. One such example is Trims, an abbreviation of Terima kasih.
Its usage is declining, however, in favour of Tq (abbreviated from "Thank you"), or simply Thanks (yes, like in English).
Thanks → You know what this means
Many aspects of the current Indonesian language are influenced by English, so this is not surprising. Younger Indonesian speakers would sometimes say Thanks ya to mean, well… “thanks”.
In Indonesian, ya is sometimes added to the end of a phrase/sentence to soften one's speech.
There we have it. Now let's find out how to respond to a “thank you” in Indonesian: