You do need an 'a' before pub.... I went to a pub last night (any pub) I went to the pub last night (could also be used but technically it assumes the person you are talking to will know which pub you mean) ------- 'I went to bed' ('bed' is used as a verb here to imply 'sleep' so it is the same as saying 'I went to sleep') 'I went to my bed' (Similar, but 'bed' is used as a noun here so does not imply sleep) 'I went to a bed' (you are saying you went to 'a' bed...who's bed?) ---------------- "I washed my face and brushed my teeth" is perfect :)

You go to a pub. Use "a" or "the" when speaking about a specific place, for example, go to the movies, drive to the airport, walk to a park. "Going to bed" is more of a phrase that means "to get in bed and sleep," so there is no article. The sentences about washing my face and brushing my teeth are perfect and natural as they are!