Article, verb and pronoun finish off grammatical block (5)
I believe the answer is:
anvil
'block' is the definition.
(I know that anvil is a type of block)
'article verb and pronoun finish off grammatical' is the wordplay.
'article' becomes 'an' (English indefinite article).
'verb' becomes 'v' (abbreviation used in dictionaries).
'and' means one lot of letters go next to another.
'pronoun' becomes 'i'.
'finish off' says to take the final letters (I've seen 'finishing off' mean this).
The last letter of 'grammatical' is 'l'.
'an'+'v'+'i'+'l'='ANVIL'
(Other definitions for anvil that I've seen before include "Smithy's last" , "Forging block" , "Heavy metal block in forge" , "Block for hammering" , "Forging equipment" .)