al-Salāmu ‘alaykum wa rahmatullāh,
One of the issues encountered when translating any text into another language is the extent to which dynamic or formal equivalence should be retained in the translation. One of the levels of connotation lost in translation relates to the semantic function of a word's morphology, and this is especially true when translating the Qur'an into English.
This concept can be further simplified and clarified by mentioning a simple rule in Arabic balaghah (rhetoric): the use of a noun indicates continuity and permanence, while the use of a verb indicates the occurence and regeneration of the act. This can be seen on some levels in English also; ponder the difference, for example, between huwa yata'allam هو يتعلم ('he is learning') and huwa muta'allim هو متعلم ('he is learned'). Both of them refer to the same essence, but the difference is that one connotes more permanence and stability than the other.
When viewed in the context of the Qur'an, the importance of such knowledge is emphasised due to the amount of meaning it conveys to the Muslim. For example, in Surah al-Anfal, Allaah mentions the following verse:
وَمَا كَانَ اللّهُ لِيُعَذِّبَهُمْ وَأَنتَ فِيهِمْ وَمَا كَانَ اللّهُ مُعَذِّبَهُمْ وَهُمْ يَسْتَغْفِرُونَ
which is translated into "And Allah would not punish them while you (Muhammad SAW) are amongst them, nor will He punish them while they seek (Allah's) Forgiveness."
Such a translation does not reflect the reality that Allaah articulated the concept of punishment using two different forms of word, one a noun (مُعَذِّبَهُمْ) and one a verb (لِيُعَذِّبَهُمْ). Thus, a more correct [albeit more clumsy-sounding] translation would be, 'Allaah would not punish them while you are among them, nor would He be their punisher while they sought His Forgiveness."
And when viewed in light of the connotations of a verb and a noun, the underlying meaning of this verse suggests: As long as Muhammad (sallaa Allaahu 'alayhi wa sallam) is among a people, Allaah will not punish them. But since he (sallaa Allaahu 'alayhi wa sallam) will only be among them for a short time and will soon pass away, this guarantee against punishment is only temporary (لِيُعَذِّبَهُمْ – verb). However, there is a way that the people can secure a continuous, permanent guarantee that Allaah will not be One who punishes them (مُعَذِّبَهُمْ – noun), and that is by seeking forgiveness from Him, even if they do not do seek the forgiveness constantly and permanently (يَسْتَغْفِرُونَ – verb).
And such is the mercy of Allaah, seen through grammar.