Editing English grammar (section)

====Relative====
{{Main|English relative clauses}}
{{For|"who/whom" and related forms|Who (pronoun)}}
The main [[relative pronoun]]s in English are ''[[who (pronoun)|who]]'' (with its derived forms ''whom'' and ''whose''), ''which'', and ''that''.<ref>Some linguists consider ''that'' in such sentences to be a [[complementizer]] rather than a relative pronoun. See [[English relative clauses#That as relativizer instead of relative pronoun|English relative clauses: Status of ''that'']].</ref>

The relative pronoun ''which'' refers to things rather than persons, as in ''the shirt, which used to be red, is faded''. For persons, ''who'' is used (''the man who saw me was tall''). The [[oblique case]] form of ''who'' is ''whom'', as in ''the man whom I saw was tall'', although in informal [[Register (sociolinguistics)|registers]] ''who'' is commonly used in place of ''whom''.

The possessive form of ''who'' is ''whose'' (for example, ''the man whose car is missing''); however the use of ''whose'' is not restricted to persons (one can say ''an idea whose time has come'').

The word ''that'' as a relative pronoun is normally found only in [[restrictive relative clause]]s (unlike ''which'' and ''who'', which can be used in both restrictive and unrestrictive clauses). It can refer to either persons or things, and cannot follow a preposition. For example, one can say ''the song that'' [or ''which''] ''I listened to yesterday'', but ''the song to which'' [not ''to that''] ''I listened yesterday''. The relative pronoun ''that'' is usually pronounced with a reduced vowel ([[schwa]]), and hence differently from the demonstrative ''that'' (see [[Weak and strong forms in English]]). If ''that'' is not the subject of the relative clause, it can be omitted (''the song I listened to yesterday'').

The word ''what'' can be used to form a [[free relative clause]] – one that has no antecedent and that serves as a complete noun phrase in itself, as in ''I like what he likes''. The words ''whatever'' and ''whichever'' can be used similarly, in the role of either pronouns (''whatever he likes'') or determiners (''whatever book he likes''). When referring to persons, ''who(ever)'' (and ''whom(ever)'') can be used in a similar way.