If you want to write English quite perfectly, you have to know some usages that are mandatory to be learnt and if misused can make your writing nothing ‘but’ a mess. One of the words that often causes headache to the ESL writers is ‘But’. But may be used as a conjunction and a preposition and be easily placed before a sentence or in the middle of a sentence.
Let’s try to look into the matter of the perfect use of But. But, as a conjunction, is generally used to join the ideas that are absolutely contrasting. Now look at the sentences where the ideas are reflected.
v The man is old but enjoys sound health
v My father is honest , but not clever
v The book is thin but packed with great ideas.
In all these sentences, the contrasting ideas are hinted at. For example, in the first sentence the man is old but he enjoys sound health that is not expected from an old man. Actually the contrasting idea is that an old man must not enjoy strong health. He must be fragile.
Now let’s use but as the preposition. As the preposition but means except, none, etc.
The boys are strong but me. In this sentence, it is clearly stated that there are many boys including I. The boys who are present they are strong but the speaker is not strong. It can be stated in this manner All the boys except me are strong.
All but my father cared for earthly pleasures. In this sentence it is mentioned in a round about way that all who lived in the time of my father cared for earthly pleasures but my father never cared for these. There is a sharp contrast that is shown quite effectively with the use of But.
Again the use of But for denotes the idea of ‘If something did not happen’. Now look at the sentence to make out the sense clearly.
v We could have enjoyed the feast but for storm the joy was marred.
From this sentence the meaning that comes out ‘ If there was no storm the feast could be enjoyed after the heart.’
Again after But the object pronoun is generally used. There is a possibility of the use of Subject pronoun in some cases too.
‘Nobody but her could do such a blunder.’ In this sentence the use seems clumsy. It is better to use the formal manner-
‘Nobody but she’. The usage is more formal.
Now we may notice that ‘cannot but and infinitive‘ may be frequently used. Even the use of cannot but help +verb+ing is used in a rampant manner. We can easily write the sentence in this manner.
v I cannot but praise your beauty.
v I cannot help praising your beauty.
Both these usages are common in English grammar.
Besides these, it is often noticed the use of but as the Adverb. Here but represents only and mean something else. But now the usages are not in basically in vogue.
v We can but commit wrong
In this sentence the meaning is ‘We can only commit wrong’. We have not learnt to do anything quite correctly.