In Chinese, 他們喜欢探訪朋友 can be translated as present or past tense. ie "They enjoy visiting their friends" or "They enjoyed visiting their friends". To explicitly be put in the past tense, one must use past time qualifiers to indicate the situation. For example, 昨天他們喜欢探訪朋友 = Yesterday, they enjoyed visiting their friends. 以前 (before), 过, 了 are all past time indicators. So without any time indicator, it is assumed to be present. However, in using future tense, the basic sentence must have a future time indicator and a word to mean that the action is yet to complete. This is 会 ("able to" or "can"). Thus, 他们將会喜欢探訪朋友 = They will enjoy visiting their friends.

他們 " 以前 / 過去 " 總是愛訪友

他们过去总是喜欢访问朋友 enjoy= 喜欢 past tense=过去

过去/以前(past tense)，他们总是喜欢去朋友家玩耍。 enjoy means‘喜欢xi3 huan1，享受xiang3 shou4’，visit means‘参观can1 guan1，游玩you2 wan2’