1. 감사했어요/감사했습니다
It's similar to "감사합니다/고마워요" but that has past tense, so it means "it was thankful." If there is someone you wanted to thank for before, then you can use this.
2. Words
1) tomorrow: 내일
2) after tomorrow: 모레
3) yesterday: 어제
4) before yesterday: 아레
5) there are n days: n일 (one days: 1일, two days: 2일)
There are some special native expressions if it is one~ten days:
하루 (one day)
이틀 (two days)
사흘 (three days)
나흘 (four days)
닷새 (five days)
엿새 (six days)
이레/일주일 (seven days)
여드레 (eight days)
아흐레 (nine days)
열흘 (ten days)
스무날 (twenty days)
There are also 열하루 (eleven days)~열아흐레 (nineteen days), but these are seldom used nowdays.
6) in n week: n주일 뒤에/n주 뒤에 (in four weeks: 4주 뒤에. This 4 is a Sino-Korean numbern so you have to read it [사], not [네]. Also, Sino-Korean numbers are usually written in Arabic number, so "사 주 뒤에" is rarely used.)
7) in n month: n달 뒤에 (in four month: 4달 뒤에/네 달 뒤에. As you can see, this 4 is a native Korean number, so you can write it as both 4 and 네, and the sound is also [네].)
You may already know this: Sino-Korean number system is usually used with Sino-Korean counting words, and native Korean numbers are usually used with native counting numbers. But I think how to distinguish them can be hard to foreigners.
Hope it helps. :)