The combination of verbs, time-period elements and negatives can form three kinds of structure ： ＂time-period elements ＋ negatives ＋ verbs＂,＂ verbs ＋ negatives ＋ time- period elements＂ and ＂ negatives ＋ verbs ＋ time-period elements＂ The grammatical meaning of the first structure is quite different from that of the latter two. The latter two structures have similar grammatical meanings. Verbs in these three structures bear different semantic features. These three structure...
