ありがとうございます vs. ありがとうございました

The English phrase “Thank you” is used regardless of the situation. You could be thanking someone for something last week, next month, it does not matter. For Japanese however you will use either ありがとうございます or  ありがとうございました depending on if you are thanking someone for a complete or an incomplete action or event.

ありがとうございます

This is use for any incomplete situations such as those that are habitual, or are still on going. So for example you would use ありがとうございます when someone gives you a gift, or they offer to help you do something. Anything that is happening now, will happen or is still not complete.

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Incomplete Situations

If you ask a friend to bring a letter to the post office for you then you would say ありがとうございます. This is because they will be going later so the action is still incomplete.

Right after short Interactions

For example, let’s say you are going to write a note and you drop a pencil. When the person next to you picks it up for you then you would say ありがとうございます. This is because the action of picking up the pencil is only a small detail or side-note to the overall process of writing. The same goes for when you get a gift. You thank the other person after receiving the gift but you are still going to enjoy the gift after the other person leaves.

Habitual Activity

A habitual activity would be anything that happens repeatedly every day, week, hour or whenever. So, if every year your grandmother sends you a birthday card you would use ありがとうございます, or more specifically you would use いつもありがとうございます. Which means,  Thank you always. The いつも is to say thank you to your grandma for not only this time but for all the years she remembered your birthday.

ありがとうございました

ありがとうございました is used after someone does something for you and the task is seen as complete. Often this will translate into when someone spends a long time or amount of effort helping you with something.

Situations in the Past

So if someone sent you a birthday card last week and you are just seeing them today, you would say ありがとうございました. You are showing gratitude for the card you received in the past and so using the past form.

Expressing a Conclusion to a Situation

Pretend you are working at a convenience store and a customer pays for their purchase and you give them their change. You would say ありがとうございました since the interaction between you and the customer is now finished.

Tricky Situations where both may be used

When asking directions you are told, take a left at the intersection and keep going. You would say ありがとうございます since this was only a side-note to your journey which concludes once you reach your destination.

Instead, if they give you a five minutes explanation of every turn, to walk two miles past the grocery store and your destination will be on the right you would say ありがとうございました. This description is more complete and the conversation was long enough to be considered a separate experience. You would say ありがとうございました as a conclusion to the conversation and also as courtesy toward the effort they put into helping you.

If you are interested in learning even more, I have reviewed what I consider the best resource for Japanese Grammar below: