Translation:I go on the metro every morning but I go on the bus every evening.
Slightly off-topic question from someone speaking English as second language only: What exactly does "go on the metro/bus" mean? I am familiar with "going by" some means of transportation and "getting on" it, also "taking" it (without preposition), but the combination "going on" is unfamiliar to me.
Tráthnóna is the time between noon and nightfall. In English, both afternoon and evening can fall during this time period, though during the winter, nightfall can occur in the late afternoon (Sunset is before 4:15 in Donegal throughout December), and "evening" can be after nightfall.