 According to the traditional approach towards sentence analysis the subject is the most important element of clause structure apart from the verb. In simple finite declarative sentences it is always present and formally it can be realized by a noun phrase as in these four examples. Alternatively subjects can be realized by a finite clause for example by a nominal that clause, a WH interrogative clause or a nominal relative clause. Furthermore they can occur as non-finite clauses as in to arrive in London or arriving in London. But how do we find out whether a noun phrase or a clause is the subject of a sentence? In last years the players made John the captain we have four noun phrases but which one is the subject. Criteria such as the subject determines the number of the verb or the subject normally occurs first do not apply here. The verb made does not exhibit number at all and the first noun phrase last year is optional. Here are two tests that can clearly identify the subject. According to the proform test a noun phrase that can be replaced by a personal pronoun in the nominative case must be the subject. Clearly this applies to the players. Its proform is the nominative marked pronoun they. A second test turns clauses with a transitive verb into the passive. There the noun phrase which can become the complement of the byphrase in the passive is the subject of the corresponding active clause. So despite its formal indeterminacy we can identify present-day English subjects using these criteria relatively well.