After the verb, the place is mentioned. A preposition is not needed.
Structure: verb + place.
他 | 回 | 德 | 国 | 。 |
tā | huí | dé | guó | _ |
he | return | virtue | country | _ |
he, him, other | return, turn round, grammatical: measure word | Germany | 。 | |
He returns to Germany. |
他 | 来 | 德 | 国 | 。 |
tā | lái | dé | guó | _ |
he | come | virtue | country | _ |
he, him, other | come, happen, connection-word | Germany | 。 | |
He comes to Germany. |
他 | 去 | 德 | 国 | 。 |
tā | qù | dé | guó | _ |
he | go | virtue | country | _ |
he, him, other | go to, pass away, remove | Germany | 。 | |
He goes to Germany. |
他 | 在 | 德 | 国 | 。 |
tā | zài | dé | guó | _ |
he | at | virtue | country | _ |
he, him, other | be at, be in, be on, be doing, 1st part: when,while | Germany | 。 | |
He is in Germany. |