Summarize the following:
" This phrase essentially means "thank you very much."  You can use arigatou gozaimasu with people who have a higher status than you, including supervisors, family elders, teachers, and strangers or acquaintances who appear older or higher in rank than you. You can also use this phrase to express formal or heartfelt gratitude to someone close to you. Pronounce arigatou gozaimasu as ah-ree-gah-toh goh-zah-ee-　mas.  In its non-romanized form, write ありがとうございます. " This is even more polite way of saying "thank you very much."  Use this phrase with those who have a higher status or in formal circumstances. You can also use the phrase to express sincerity with someone familiar. Pronounce the phrase as dough-moh ah-ree-gah-toh goh-zah-ee-mas.'  In its non-romanized form, write domo arigatou gozaimasu as どうもございまずいます. " If someone has done something for you in the recent past, make the phrase past tense by changing the -u ending of gozaimasu to -ita. Pronounce the phrase as ah-ree-gah-toh go-za-ee-ma-shi-tah.

Summary:
State "arigatou gozaimasu. Switch to "domo arigatou gozaimasu. Express thanks in the past tense as "arigatou gozaimashita.