Present — what is happening now, and what happens habitually
| yo | empiezoI begin | nosotros | empezamoswe begin |
| tú | empiezasyou begin | vosotros | empezáisyou all begin |
| él/ella/Ud. | empiezahe/she begins | ellos/Uds. | empiezanthey begin |
Present perfect — have —ed; a past still touching now. Spain: today, this week. Latin America: mostly the indefinido instead
| yo | he empezadoI have begun | nosotros | hemos empezadowe have begun |
| tú | has empezadoyou have begun | vosotros | habéis empezadoyou all have begun |
| él/ella/Ud. | ha empezadohe/she has begun | ellos/Uds. | han empezadothey have begun |
Present subjunctive — after que with wishes, doubt, emotion, ojalá
| yo | empiece(that) I begin | nosotros | empecemos(that) we begin |
| tú | empieces(that) you begin | vosotros | empecéis(that) you all begin |
| él/ella/Ud. | empiece(that) he/she begins | ellos/Uds. | empiecen(that) they begin |
Present perfect subjunctive — have —ed, under doubt or emotion: no creo que haya venido
| yo | haya empezado(that) I have begun | nosotros | hayamos empezado(that) we have begun |
| tú | hayas empezado(that) you have begun | vosotros | hayáis empezado(that) you all have begun |
| él/ella/Ud. | haya empezado(that) he/she has begun | ellos/Uds. | hayan empezado(that) they have begun |
Preterite — a finished past action — it started, it ended
| yo | empecéI began | nosotros | empezamoswe began |
| tú | empezasteyou began | vosotros | empezasteisyou all began |
| él/ella/Ud. | empezóhe/she began | ellos/Uds. | empezaronthey began |
Imperfect — used to / was —ing; background, habits, descriptions
| yo | empezabaI used to begin | nosotros | empezábamoswe used to begin |
| tú | empezabasyou used to begin | vosotros | empezabaisyou all used to begin |
| él/ella/Ud. | empezabahe/she used to begin | ellos/Uds. | empezabanthey used to begin |
Past perfect — had —ed; further back than another past event
| yo | había empezadoI had begun | nosotros | habíamos empezadowe had begun |
| tú | habías empezadoyou had begun | vosotros | habíais empezadoyou all had begun |
| él/ella/Ud. | había empezadohe/she had begun | ellos/Uds. | habían empezadothey had begun |
Imperfect subjunctive — si clauses and past-tense wishes: si tuviera, quería que fuera
| yo | empezara(that) I began | nosotros | empezáramos(that) we began |
| tú | empezaras(that) you began | vosotros | empezarais(that) you all began |
| él/ella/Ud. | empezara(that) he/she began | ellos/Uds. | empezaran(that) they began |
Imperfect subjunctive — the same tense, second form; commoner in Spain and in writing
| yo | empezase(that) I began | nosotros | empezásemos(that) we began |
| tú | empezases(that) you began | vosotros | empezaseis(that) you all began |
| él/ella/Ud. | empezase(that) he/she began | ellos/Uds. | empezasen(that) they began |
Past perfect subjunctive — had —ed, hypothetically: si hubiera sabido
| yo | hubiera empezado(that) I had begun | nosotros | hubiéramos empezado(that) we had begun |
| tú | hubieras empezado(that) you had begun | vosotros | hubierais empezado(that) you all had begun |
| él/ella/Ud. | hubiera empezado(that) he/she had begun | ellos/Uds. | hubieran empezado(that) they had begun |
Preterite perfect — had —ed, immediately before; literary, all but extinct
| yo | hube empezadoI had begun | nosotros | hubimos empezadowe had begun |
| tú | hubiste empezadoyou had begun | vosotros | hubisteis empezadoyou all had begun |
| él/ella/Ud. | hubo empezadohe/she had begun | ellos/Uds. | hubieron empezadothey had begun |
Future — will — (spoken Spanish often prefers voy a + infinitivo)
| yo | empezaréI will begin | nosotros | empezaremoswe will begin |
| tú | empezarásyou will begin | vosotros | empezaréisyou all will begin |
| él/ella/Ud. | empezaráhe/she will begin | ellos/Uds. | empezaránthey will begin |
Conditional — would —; also softens a request into politeness
| yo | empezaríaI would begin | nosotros | empezaríamoswe would begin |
| tú | empezaríasyou would begin | vosotros | empezaríaisyou all would begin |
| él/ella/Ud. | empezaríahe/she would begin | ellos/Uds. | empezaríanthey would begin |
Future perfect — will have —ed; done by some future point
| yo | habré empezadoI will have begun | nosotros | habremos empezadowe will have begun |
| tú | habrás empezadoyou will have begun | vosotros | habréis empezadoyou all will have begun |
| él/ella/Ud. | habrá empezadohe/she will have begun | ellos/Uds. | habrán empezadothey will have begun |
Conditional perfect — would have —ed; the road not taken
| yo | habría empezadoI would have begun | nosotros | habríamos empezadowe would have begun |
| tú | habrías empezadoyou would have begun | vosotros | habríais empezadoyou all would have begun |
| él/ella/Ud. | habría empezadohe/she would have begun | ellos/Uds. | habrían empezadothey would have begun |
Future subjunctive — legal and proverbial only: adonde fueres, haz lo que vieres
| yo | empezare(should) I begin | nosotros | empezáremos(should) we begin |
| tú | empezares(should) you begin | vosotros | empezareis(should) you all begin |
| él/ella/Ud. | empezare(should) he/she begin | ellos/Uds. | empezaren(should) they begin |
Imperative (do it) — orders and requests; there is no yo form
| yo | — | nosotros | empecemoslet's begin |
| tú | empiezabegin! | vosotros | empezadbegin! |
| él/ella/Ud. | empiecebegin! | ellos/Uds. | empiecenbegin! |
Imperative (don't) — no + subjunctive — never the affirmative form with no in front
| yo | — | nosotros | no empecemoslet's not begin |
| tú | no empiecesdon't begin | vosotros | no empecéisdon't begin |
| él/ella/Ud. | no empiecedon't begin | ellos/Uds. | no empiecendon't begin |

Red = the form breaks the regular pattern. Everything in black you could have worked out from the endings alone.
I — the speaker
| Presente | empiezoI begin |
| Perfecto | he empezadoI have begun |
| Subj. presente | empiece(that) I begin |
| Subj. perfecto | haya empezado(that) I have begun |
| Futuro | empezaréI will begin |
| Condicional | empezaríaI would begin |
| Fut. perfecto | habré empezadoI will have begun |
| Cond. perfecto | habría empezadoI would have begun |
| Subj. futuro | empezare(should) I begin |
| Indefinido | empecéI began |
| Imperfecto | empezabaI used to begin |
| Pluscuamp. | había empezadoI had begun |
| Subj. imperf. | empezara(that) I began |
| Subj. -se | empezase(that) I began |
| Subj. pluscuamp. | hubiera empezado(that) I had begun |
| Pret. anterior | hube empezadoI had begun |
| Imperativo | — |
| Imper. negativo | — |
we — the speaker plus others
| Presente | empezamoswe begin |
| Perfecto | hemos empezadowe have begun |
| Subj. presente | empecemos(that) we begin |
| Subj. perfecto | hayamos empezado(that) we have begun |
| Futuro | empezaremoswe will begin |
| Condicional | empezaríamoswe would begin |
| Fut. perfecto | habremos empezadowe will have begun |
| Cond. perfecto | habríamos empezadowe would have begun |
| Subj. futuro | empezáremos(should) we begin |
| Indefinido | empezamoswe began |
| Imperfecto | empezábamoswe used to begin |
| Pluscuamp. | habíamos empezadowe had begun |
| Subj. imperf. | empezáramos(that) we began |
| Subj. -se | empezásemos(that) we began |
| Subj. pluscuamp. | hubiéramos empezado(that) we had begun |
| Pret. anterior | hubimos empezadowe had begun |
| Imperativo | empecemoslet's begin |
| Imper. negativo | no empecemoslet's not begin |
you (informal) — one person you are familiar with
| Presente | empiezasyou begin |
| Perfecto | has empezadoyou have begun |
| Subj. presente | empieces(that) you begin |
| Subj. perfecto | hayas empezado(that) you have begun |
| Futuro | empezarásyou will begin |
| Condicional | empezaríasyou would begin |
| Fut. perfecto | habrás empezadoyou will have begun |
| Cond. perfecto | habrías empezadoyou would have begun |
| Subj. futuro | empezares(should) you begin |
| Indefinido | empezasteyou began |
| Imperfecto | empezabasyou used to begin |
| Pluscuamp. | habías empezadoyou had begun |
| Subj. imperf. | empezaras(that) you began |
| Subj. -se | empezases(that) you began |
| Subj. pluscuamp. | hubieras empezado(that) you had begun |
| Pret. anterior | hubiste empezadoyou had begun |
| Imperativo | empiezabegin! |
| Imper. negativo | no empiecesdon't begin |
you all — informal plural, Spain only
| Presente | empezáisyou all begin |
| Perfecto | habéis empezadoyou all have begun |
| Subj. presente | empecéis(that) you all begin |
| Subj. perfecto | hayáis empezado(that) you all have begun |
| Futuro | empezaréisyou all will begin |
| Condicional | empezaríaisyou all would begin |
| Fut. perfecto | habréis empezadoyou all will have begun |
| Cond. perfecto | habríais empezadoyou all would have begun |
| Subj. futuro | empezareis(should) you all begin |
| Indefinido | empezasteisyou all began |
| Imperfecto | empezabaisyou all used to begin |
| Pluscuamp. | habíais empezadoyou all had begun |
| Subj. imperf. | empezarais(that) you all began |
| Subj. -se | empezaseis(that) you all began |
| Subj. pluscuamp. | hubierais empezado(that) you all had begun |
| Pret. anterior | hubisteis empezadoyou all had begun |
| Imperativo | empezadbegin! |
| Imper. negativo | no empecéisdon't begin |
he, she, you (formal) — one other person — formal you shares it
| Presente | empiezahe/she begins |
| Perfecto | ha empezadohe/she has begun |
| Subj. presente | empiece(that) he/she begins |
| Subj. perfecto | haya empezado(that) he/she has begun |
| Futuro | empezaráhe/she will begin |
| Condicional | empezaríahe/she would begin |
| Fut. perfecto | habrá empezadohe/she will have begun |
| Cond. perfecto | habría empezadohe/she would have begun |
| Subj. futuro | empezare(should) he/she begin |
| Indefinido | empezóhe/she began |
| Imperfecto | empezabahe/she used to begin |
| Pluscuamp. | había empezadohe/she had begun |
| Subj. imperf. | empezara(that) he/she began |
| Subj. -se | empezase(that) he/she began |
| Subj. pluscuamp. | hubiera empezado(that) he/she had begun |
| Pret. anterior | hubo empezadohe/she had begun |
| Imperativo | empiecebegin! |
| Imper. negativo | no empiecedon't begin |
they, you all — several others — plural you shares it
| Presente | empiezanthey begin |
| Perfecto | han empezadothey have begun |
| Subj. presente | empiecen(that) they begin |
| Subj. perfecto | hayan empezado(that) they have begun |
| Futuro | empezaránthey will begin |
| Condicional | empezaríanthey would begin |
| Fut. perfecto | habrán empezadothey will have begun |
| Cond. perfecto | habrían empezadothey would have begun |
| Subj. futuro | empezaren(should) they begin |
| Indefinido | empezaronthey began |
| Imperfecto | empezabanthey used to begin |
| Pluscuamp. | habían empezadothey had begun |
| Subj. imperf. | empezaran(that) they began |
| Subj. -se | empezasen(that) they began |
| Subj. pluscuamp. | hubieran empezado(that) they had begun |
| Pret. anterior | hubieron empezadothey had begun |
| Imperativo | empiecenbegin! |
| Imper. negativo | no empiecendon't begin |

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