1.2. Tenses and Aspects

Expression	Relation
had	$\(TT=\)$ past, $\(E<TT\)$
had been	$\(TT=\)$ past, $\(S<TT,\)$ $\(E=\)$ progressive
was	$\(TT=\)$ past, $\(E=\)$ progressive
have	$\(TT=\)$ present, $\(E<TT\)$
have been	$\(TT=\)$ present, $\(S<TT,\)$ $\(E=\)$ progressive
is	$\(TT=\)$ present, $\(E=\)$ progressive
will be	$\(TT=\)$ future, $\(E=\)$ progressive
will have	$\(TT=\)$ future, $\(E<TT\)$
will have been	$\(TT=\)$ future, $\(S<TT,\)$ $\(E=\)$ progressive