In Lesson 27 the word GUO has me confused as it is referred differently, e.g. have,before,celebrate,I understand it means expressing the completion of an action or crossing over!!!.,so have is past tense,beforeis past tense and is celebrate is not until the d is added.
You are right, Guò has two meanings:
1) as a verb it means “to pass” or “to celebrate” e.g.:
– 过年 GuòNián spend/celebrate (Chinese) New Year
– 过圣诞节 Guò ShèngDànJié spend/celebrate Christmas (this is the example from the lesson)
2) as a particle, Guò has the meaning of “having been done before”, so expressing a past experience, either:
a) to have done something ever before in one’s life e.g.
– 你来过纽约吗? Nǐ Lái Guò NiǔYuē Mā? Have you come/been to New York before? (this is the example from the lesson)
– 你去过中国吗？ Nǐ Qù Guò ZhōngGuó Ma? Have you been to China?
b) to have done something which one does regularly (i.e., this year, this month, this week, today, etc.) e.g.
– 吃饭了吗？ ChīFàn Le Ma? Have you eaten yet?
吃过了，谢谢。Chī Guò Le, XìeXie. Yes I have, thanks.