Most finite sentences have a phrase labelled NP-SBJ, which can be lexicalized or null (on the position and the codification of null subjects, see more details under Null Subjects).

(IP-MAT   (NP-SBJ  (D Aquele)                 ☜ preverbal subject
                   (N buraco))
          (VB-P-3S enfia)
          (PP  (P @em)
               (NP  (D @o)
                     (N tolete))))
(CORDIAL-SIN; ID VPA02)

( (IP-MAT (NP-SBJ (DEM Isto))                 ☜ preverbal subject
	  (NEG não)
	  (SR-P é)
	  (PP (FP só)
	      (P em@)
	      (D @o)
	      (NP (N amor)))
	  (. ;))
(TYCHO BRAHE; ID A_001_PSD,89.2006))

(IP-MAT-PRN   (TR-D-1S tinha)
              (NP-SBJ (PRO eu))               ☜ agreeing postverbal subject
              (NP-ACC (NUM (NUM vinte)
                           (CONJ e)
                           (NUM cinco))
                       (N-P anos)))
              (. .))
(CORDIAL-SIN; ID VPA04)

(IP-MAT   (NP-SBJ *pro*)                      ☜ null referential subject
          (VB-D-1S Fiz)
          (NP-ACC  (D-F a)
                   (ADJ-F primeira)
                   (N viagem))
          (PP  (P em)
               (NP (NUM 46)))
          (. .))
(CORDIAL-SIN; ID VPA05)

( (IP-MAT (NP-SBJ *pro*)                      ☜ null referential subject
	  (VB-D Declamei)
	  (PP (P contra)
	      (NP (D-F a) (N vaidade)))
	  (. ,))
(TYCHO BRAHE; ID A_001_PSD,03.3))

( (IP-MAT (IP-MAT (NP-SBJ *exp*)              ☜ null expletive subject
		  (NP-ADV (Q-G Cada) (N vez))
		  (HV-P há)
		  (NP-ACC (ADJ-R-G-P maiores) (N-P desordens)))
	  [...]
   (POST SCRIPTUM; ID CARDS0018,.6))

Null subjects are not annotated in the following tensed contexts:

( (IP-IMP-SPE (NP-VOC (INTJ ó)
                      (NPR Senhor_Aristarco))
              (, ,)
              (VB-SP-3S tome)
              (FP lá)
              (NP-ACC (D-F a)
                      (N chave)))
              (QT ")
              [...]
              (. .))
  (CORDIAL-SIN; ID VPA20))

( (IP-MAT (NP-SBJ-1 *exp*)
	  (SR-P-3S É)
	  (NP-1 (D o)
		(N hábito)
		(PP (P @de)
		    (NP (D-F @a) (N fala))))
	  (, ,)
	  (IP-POL (SR-P-3S é))
	  (. .))
   (CORDIAL-SIN; ID CBV07,25))

E chamam-lhe meixão?
( (IP-ANS  (VB-P-3P Chamam)
           (. .))
  (CORDIAL-SIN; ID VPA10))

( (IP-MAT (NP-SBJ *pro*)
          (TR-P-3P têm)
          (NP-ACC  (D-UM um)
                   (N bocadinho)
                   (PP  (P de)
                        (NP (N ferrugem))))
          (, ,)
          (CP-QUE-TAG   (NEG não)
                        (TR-P-3P têm))
          (. ?))
  (CORDIAL-SIN; ID VPA36))