Present — what is happening now, and what happens habitually
| yo | supongoI suppose | nosotros | suponemoswe suppose |
| tú | suponesyou suppose | vosotros | suponéisyou all suppose |
| él/ella/Ud. | suponehe/she supposes | ellos/Uds. | suponenthey suppose |
Present perfect — have —ed; a past still touching now. Spain: today, this week. Latin America: mostly the indefinido instead
| yo | he supuestoI have supposed | nosotros | hemos supuestowe have supposed |
| tú | has supuestoyou have supposed | vosotros | habéis supuestoyou all have supposed |
| él/ella/Ud. | ha supuestohe/she has supposed | ellos/Uds. | han supuestothey have supposed |
Present subjunctive — after que with wishes, doubt, emotion, ojalá
| yo | suponga(that) I suppose | nosotros | supongamos(that) we suppose |
| tú | supongas(that) you suppose | vosotros | supongáis(that) you all suppose |
| él/ella/Ud. | suponga(that) he/she supposes | ellos/Uds. | supongan(that) they suppose |
Present perfect subjunctive — have —ed, under doubt or emotion: no creo que haya venido
| yo | haya supuesto(that) I have supposed | nosotros | hayamos supuesto(that) we have supposed |
| tú | hayas supuesto(that) you have supposed | vosotros | hayáis supuesto(that) you all have supposed |
| él/ella/Ud. | haya supuesto(that) he/she has supposed | ellos/Uds. | hayan supuesto(that) they have supposed |
Preterite — a finished past action — it started, it ended
| yo | supuseI supposed | nosotros | supusimoswe supposed |
| tú | supusisteyou supposed | vosotros | supusisteisyou all supposed |
| él/ella/Ud. | supusohe/she supposed | ellos/Uds. | supusieronthey supposed |
Imperfect — used to / was —ing; background, habits, descriptions
| yo | suponíaI used to suppose | nosotros | suponíamoswe used to suppose |
| tú | suponíasyou used to suppose | vosotros | suponíaisyou all used to suppose |
| él/ella/Ud. | suponíahe/she used to suppose | ellos/Uds. | suponíanthey used to suppose |
Past perfect — had —ed; further back than another past event
| yo | había supuestoI had supposed | nosotros | habíamos supuestowe had supposed |
| tú | habías supuestoyou had supposed | vosotros | habíais supuestoyou all had supposed |
| él/ella/Ud. | había supuestohe/she had supposed | ellos/Uds. | habían supuestothey had supposed |
Imperfect subjunctive — si clauses and past-tense wishes: si tuviera, quería que fuera
| yo | supusiera(that) I supposed | nosotros | supusiéramos(that) we supposed |
| tú | supusieras(that) you supposed | vosotros | supusierais(that) you all supposed |
| él/ella/Ud. | supusiera(that) he/she supposed | ellos/Uds. | supusieran(that) they supposed |
Imperfect subjunctive — the same tense, second form; commoner in Spain and in writing
| yo | supusiese(that) I supposed | nosotros | supusiésemos(that) we supposed |
| tú | supusieses(that) you supposed | vosotros | supusieseis(that) you all supposed |
| él/ella/Ud. | supusiese(that) he/she supposed | ellos/Uds. | supusiesen(that) they supposed |
Past perfect subjunctive — had —ed, hypothetically: si hubiera sabido
| yo | hubiera supuesto(that) I had supposed | nosotros | hubiéramos supuesto(that) we had supposed |
| tú | hubieras supuesto(that) you had supposed | vosotros | hubierais supuesto(that) you all had supposed |
| él/ella/Ud. | hubiera supuesto(that) he/she had supposed | ellos/Uds. | hubieran supuesto(that) they had supposed |
Preterite perfect — had —ed, immediately before; literary, all but extinct
| yo | hube supuestoI had supposed | nosotros | hubimos supuestowe had supposed |
| tú | hubiste supuestoyou had supposed | vosotros | hubisteis supuestoyou all had supposed |
| él/ella/Ud. | hubo supuestohe/she had supposed | ellos/Uds. | hubieron supuestothey had supposed |
Future — will — (spoken Spanish often prefers voy a + infinitivo)
| yo | supondréI will suppose | nosotros | supondremoswe will suppose |
| tú | supondrásyou will suppose | vosotros | supondréisyou all will suppose |
| él/ella/Ud. | supondráhe/she will suppose | ellos/Uds. | supondránthey will suppose |
Conditional — would —; also softens a request into politeness
| yo | supondríaI would suppose | nosotros | supondríamoswe would suppose |
| tú | supondríasyou would suppose | vosotros | supondríaisyou all would suppose |
| él/ella/Ud. | supondríahe/she would suppose | ellos/Uds. | supondríanthey would suppose |
Future perfect — will have —ed; done by some future point
| yo | habré supuestoI will have supposed | nosotros | habremos supuestowe will have supposed |
| tú | habrás supuestoyou will have supposed | vosotros | habréis supuestoyou all will have supposed |
| él/ella/Ud. | habrá supuestohe/she will have supposed | ellos/Uds. | habrán supuestothey will have supposed |
Conditional perfect — would have —ed; the road not taken
| yo | habría supuestoI would have supposed | nosotros | habríamos supuestowe would have supposed |
| tú | habrías supuestoyou would have supposed | vosotros | habríais supuestoyou all would have supposed |
| él/ella/Ud. | habría supuestohe/she would have supposed | ellos/Uds. | habrían supuestothey would have supposed |
Future subjunctive — legal and proverbial only: adonde fueres, haz lo que vieres
| yo | supusiere(should) I suppose | nosotros | supusiéremos(should) we suppose |
| tú | supusieres(should) you suppose | vosotros | supusiereis(should) you all suppose |
| él/ella/Ud. | supusiere(should) he/she suppose | ellos/Uds. | supusieren(should) they suppose |
Imperative (do it) — orders and requests; there is no yo form
| yo | — | nosotros | supongamoslet's suppose |
| tú | supónsuppose! | vosotros | suponedsuppose! |
| él/ella/Ud. | supongasuppose! | ellos/Uds. | supongansuppose! |
Imperative (don't) — no + subjunctive — never the affirmative form with no in front
| yo | — | nosotros | no supongamoslet's not suppose |
| tú | no supongasdon't suppose | vosotros | no supongáisdon't suppose |
| él/ella/Ud. | no supongadon't suppose | ellos/Uds. | no supongandon't suppose |

Red = the form breaks the regular pattern. Everything in black you could have worked out from the endings alone.
I — the speaker
| Presente | supongoI suppose |
| Perfecto | he supuestoI have supposed |
| Subj. presente | suponga(that) I suppose |
| Subj. perfecto | haya supuesto(that) I have supposed |
| Futuro | supondréI will suppose |
| Condicional | supondríaI would suppose |
| Fut. perfecto | habré supuestoI will have supposed |
| Cond. perfecto | habría supuestoI would have supposed |
| Subj. futuro | supusiere(should) I suppose |
| Indefinido | supuseI supposed |
| Imperfecto | suponíaI used to suppose |
| Pluscuamp. | había supuestoI had supposed |
| Subj. imperf. | supusiera(that) I supposed |
| Subj. -se | supusiese(that) I supposed |
| Subj. pluscuamp. | hubiera supuesto(that) I had supposed |
| Pret. anterior | hube supuestoI had supposed |
| Imperativo | — |
| Imper. negativo | — |
we — the speaker plus others
| Presente | suponemoswe suppose |
| Perfecto | hemos supuestowe have supposed |
| Subj. presente | supongamos(that) we suppose |
| Subj. perfecto | hayamos supuesto(that) we have supposed |
| Futuro | supondremoswe will suppose |
| Condicional | supondríamoswe would suppose |
| Fut. perfecto | habremos supuestowe will have supposed |
| Cond. perfecto | habríamos supuestowe would have supposed |
| Subj. futuro | supusiéremos(should) we suppose |
| Indefinido | supusimoswe supposed |
| Imperfecto | suponíamoswe used to suppose |
| Pluscuamp. | habíamos supuestowe had supposed |
| Subj. imperf. | supusiéramos(that) we supposed |
| Subj. -se | supusiésemos(that) we supposed |
| Subj. pluscuamp. | hubiéramos supuesto(that) we had supposed |
| Pret. anterior | hubimos supuestowe had supposed |
| Imperativo | supongamoslet's suppose |
| Imper. negativo | no supongamoslet's not suppose |
you (informal) — one person you are familiar with
| Presente | suponesyou suppose |
| Perfecto | has supuestoyou have supposed |
| Subj. presente | supongas(that) you suppose |
| Subj. perfecto | hayas supuesto(that) you have supposed |
| Futuro | supondrásyou will suppose |
| Condicional | supondríasyou would suppose |
| Fut. perfecto | habrás supuestoyou will have supposed |
| Cond. perfecto | habrías supuestoyou would have supposed |
| Subj. futuro | supusieres(should) you suppose |
| Indefinido | supusisteyou supposed |
| Imperfecto | suponíasyou used to suppose |
| Pluscuamp. | habías supuestoyou had supposed |
| Subj. imperf. | supusieras(that) you supposed |
| Subj. -se | supusieses(that) you supposed |
| Subj. pluscuamp. | hubieras supuesto(that) you had supposed |
| Pret. anterior | hubiste supuestoyou had supposed |
| Imperativo | supónsuppose! |
| Imper. negativo | no supongasdon't suppose |
you all — informal plural, Spain only
| Presente | suponéisyou all suppose |
| Perfecto | habéis supuestoyou all have supposed |
| Subj. presente | supongáis(that) you all suppose |
| Subj. perfecto | hayáis supuesto(that) you all have supposed |
| Futuro | supondréisyou all will suppose |
| Condicional | supondríaisyou all would suppose |
| Fut. perfecto | habréis supuestoyou all will have supposed |
| Cond. perfecto | habríais supuestoyou all would have supposed |
| Subj. futuro | supusiereis(should) you all suppose |
| Indefinido | supusisteisyou all supposed |
| Imperfecto | suponíaisyou all used to suppose |
| Pluscuamp. | habíais supuestoyou all had supposed |
| Subj. imperf. | supusierais(that) you all supposed |
| Subj. -se | supusieseis(that) you all supposed |
| Subj. pluscuamp. | hubierais supuesto(that) you all had supposed |
| Pret. anterior | hubisteis supuestoyou all had supposed |
| Imperativo | suponedsuppose! |
| Imper. negativo | no supongáisdon't suppose |
he, she, you (formal) — one other person — formal you shares it
| Presente | suponehe/she supposes |
| Perfecto | ha supuestohe/she has supposed |
| Subj. presente | suponga(that) he/she supposes |
| Subj. perfecto | haya supuesto(that) he/she has supposed |
| Futuro | supondráhe/she will suppose |
| Condicional | supondríahe/she would suppose |
| Fut. perfecto | habrá supuestohe/she will have supposed |
| Cond. perfecto | habría supuestohe/she would have supposed |
| Subj. futuro | supusiere(should) he/she suppose |
| Indefinido | supusohe/she supposed |
| Imperfecto | suponíahe/she used to suppose |
| Pluscuamp. | había supuestohe/she had supposed |
| Subj. imperf. | supusiera(that) he/she supposed |
| Subj. -se | supusiese(that) he/she supposed |
| Subj. pluscuamp. | hubiera supuesto(that) he/she had supposed |
| Pret. anterior | hubo supuestohe/she had supposed |
| Imperativo | supongasuppose! |
| Imper. negativo | no supongadon't suppose |
they, you all — several others — plural you shares it
| Presente | suponenthey suppose |
| Perfecto | han supuestothey have supposed |
| Subj. presente | supongan(that) they suppose |
| Subj. perfecto | hayan supuesto(that) they have supposed |
| Futuro | supondránthey will suppose |
| Condicional | supondríanthey would suppose |
| Fut. perfecto | habrán supuestothey will have supposed |
| Cond. perfecto | habrían supuestothey would have supposed |
| Subj. futuro | supusieren(should) they suppose |
| Indefinido | supusieronthey supposed |
| Imperfecto | suponíanthey used to suppose |
| Pluscuamp. | habían supuestothey had supposed |
| Subj. imperf. | supusieran(that) they supposed |
| Subj. -se | supusiesen(that) they supposed |
| Subj. pluscuamp. | hubieran supuesto(that) they had supposed |
| Pret. anterior | hubieron supuestothey had supposed |
| Imperativo | supongansuppose! |
| Imper. negativo | no supongandon't suppose |

Red = the form breaks the regular pattern. Everything in black you could have worked out from the endings alone.