Present — what is happening now, and what happens habitually
| yo | siembroI sow | nosotros | sembramoswe sow |
| tú | siembrasyou sow | vosotros | sembráisyou all sow |
| él/ella/Ud. | siembrahe/she sows | ellos/Uds. | siembranthey sow |
Present perfect — have —ed; a past still touching now. Spain: today, this week. Latin America: mostly the indefinido instead
| yo | he sembradoI have sowed | nosotros | hemos sembradowe have sowed |
| tú | has sembradoyou have sowed | vosotros | habéis sembradoyou all have sowed |
| él/ella/Ud. | ha sembradohe/she has sowed | ellos/Uds. | han sembradothey have sowed |
Present subjunctive — after que with wishes, doubt, emotion, ojalá
| yo | siembre(that) I sow | nosotros | sembremos(that) we sow |
| tú | siembres(that) you sow | vosotros | sembréis(that) you all sow |
| él/ella/Ud. | siembre(that) he/she sows | ellos/Uds. | siembren(that) they sow |
Present perfect subjunctive — have —ed, under doubt or emotion: no creo que haya venido
| yo | haya sembrado(that) I have sowed | nosotros | hayamos sembrado(that) we have sowed |
| tú | hayas sembrado(that) you have sowed | vosotros | hayáis sembrado(that) you all have sowed |
| él/ella/Ud. | haya sembrado(that) he/she has sowed | ellos/Uds. | hayan sembrado(that) they have sowed |
Preterite — a finished past action — it started, it ended
| yo | sembréI sowed | nosotros | sembramoswe sowed |
| tú | sembrasteyou sowed | vosotros | sembrasteisyou all sowed |
| él/ella/Ud. | sembróhe/she sowed | ellos/Uds. | sembraronthey sowed |
Imperfect — used to / was —ing; background, habits, descriptions
| yo | sembrabaI used to sow | nosotros | sembrábamoswe used to sow |
| tú | sembrabasyou used to sow | vosotros | sembrabaisyou all used to sow |
| él/ella/Ud. | sembrabahe/she used to sow | ellos/Uds. | sembrabanthey used to sow |
Past perfect — had —ed; further back than another past event
| yo | había sembradoI had sowed | nosotros | habíamos sembradowe had sowed |
| tú | habías sembradoyou had sowed | vosotros | habíais sembradoyou all had sowed |
| él/ella/Ud. | había sembradohe/she had sowed | ellos/Uds. | habían sembradothey had sowed |
Imperfect subjunctive — si clauses and past-tense wishes: si tuviera, quería que fuera
| yo | sembrara(that) I sowed | nosotros | sembráramos(that) we sowed |
| tú | sembraras(that) you sowed | vosotros | sembrarais(that) you all sowed |
| él/ella/Ud. | sembrara(that) he/she sowed | ellos/Uds. | sembraran(that) they sowed |
Imperfect subjunctive — the same tense, second form; commoner in Spain and in writing
| yo | sembrase(that) I sowed | nosotros | sembrásemos(that) we sowed |
| tú | sembrases(that) you sowed | vosotros | sembraseis(that) you all sowed |
| él/ella/Ud. | sembrase(that) he/she sowed | ellos/Uds. | sembrasen(that) they sowed |
Past perfect subjunctive — had —ed, hypothetically: si hubiera sabido
| yo | hubiera sembrado(that) I had sowed | nosotros | hubiéramos sembrado(that) we had sowed |
| tú | hubieras sembrado(that) you had sowed | vosotros | hubierais sembrado(that) you all had sowed |
| él/ella/Ud. | hubiera sembrado(that) he/she had sowed | ellos/Uds. | hubieran sembrado(that) they had sowed |
Preterite perfect — had —ed, immediately before; literary, all but extinct
| yo | hube sembradoI had sowed | nosotros | hubimos sembradowe had sowed |
| tú | hubiste sembradoyou had sowed | vosotros | hubisteis sembradoyou all had sowed |
| él/ella/Ud. | hubo sembradohe/she had sowed | ellos/Uds. | hubieron sembradothey had sowed |
Future — will — (spoken Spanish often prefers voy a + infinitivo)
| yo | sembraréI will sow | nosotros | sembraremoswe will sow |
| tú | sembrarásyou will sow | vosotros | sembraréisyou all will sow |
| él/ella/Ud. | sembraráhe/she will sow | ellos/Uds. | sembraránthey will sow |
Conditional — would —; also softens a request into politeness
| yo | sembraríaI would sow | nosotros | sembraríamoswe would sow |
| tú | sembraríasyou would sow | vosotros | sembraríaisyou all would sow |
| él/ella/Ud. | sembraríahe/she would sow | ellos/Uds. | sembraríanthey would sow |
Future perfect — will have —ed; done by some future point
| yo | habré sembradoI will have sowed | nosotros | habremos sembradowe will have sowed |
| tú | habrás sembradoyou will have sowed | vosotros | habréis sembradoyou all will have sowed |
| él/ella/Ud. | habrá sembradohe/she will have sowed | ellos/Uds. | habrán sembradothey will have sowed |
Conditional perfect — would have —ed; the road not taken
| yo | habría sembradoI would have sowed | nosotros | habríamos sembradowe would have sowed |
| tú | habrías sembradoyou would have sowed | vosotros | habríais sembradoyou all would have sowed |
| él/ella/Ud. | habría sembradohe/she would have sowed | ellos/Uds. | habrían sembradothey would have sowed |
Future subjunctive — legal and proverbial only: adonde fueres, haz lo que vieres
| yo | sembrare(should) I sow | nosotros | sembráremos(should) we sow |
| tú | sembrares(should) you sow | vosotros | sembrareis(should) you all sow |
| él/ella/Ud. | sembrare(should) he/she sow | ellos/Uds. | sembraren(should) they sow |
Imperative (do it) — orders and requests; there is no yo form
| yo | — | nosotros | sembremoslet's sow |
| tú | siembrasow! | vosotros | sembradsow! |
| él/ella/Ud. | siembresow! | ellos/Uds. | siembrensow! |
Imperative (don't) — no + subjunctive — never the affirmative form with no in front
| yo | — | nosotros | no sembremoslet's not sow |
| tú | no siembresdon't sow | vosotros | no sembréisdon't sow |
| él/ella/Ud. | no siembredon't sow | ellos/Uds. | no siembrendon't sow |

Red = the form breaks the regular pattern. Everything in black you could have worked out from the endings alone.
I — the speaker
| Presente | siembroI sow |
| Perfecto | he sembradoI have sowed |
| Subj. presente | siembre(that) I sow |
| Subj. perfecto | haya sembrado(that) I have sowed |
| Futuro | sembraréI will sow |
| Condicional | sembraríaI would sow |
| Fut. perfecto | habré sembradoI will have sowed |
| Cond. perfecto | habría sembradoI would have sowed |
| Subj. futuro | sembrare(should) I sow |
| Indefinido | sembréI sowed |
| Imperfecto | sembrabaI used to sow |
| Pluscuamp. | había sembradoI had sowed |
| Subj. imperf. | sembrara(that) I sowed |
| Subj. -se | sembrase(that) I sowed |
| Subj. pluscuamp. | hubiera sembrado(that) I had sowed |
| Pret. anterior | hube sembradoI had sowed |
| Imperativo | — |
| Imper. negativo | — |
we — the speaker plus others
| Presente | sembramoswe sow |
| Perfecto | hemos sembradowe have sowed |
| Subj. presente | sembremos(that) we sow |
| Subj. perfecto | hayamos sembrado(that) we have sowed |
| Futuro | sembraremoswe will sow |
| Condicional | sembraríamoswe would sow |
| Fut. perfecto | habremos sembradowe will have sowed |
| Cond. perfecto | habríamos sembradowe would have sowed |
| Subj. futuro | sembráremos(should) we sow |
| Indefinido | sembramoswe sowed |
| Imperfecto | sembrábamoswe used to sow |
| Pluscuamp. | habíamos sembradowe had sowed |
| Subj. imperf. | sembráramos(that) we sowed |
| Subj. -se | sembrásemos(that) we sowed |
| Subj. pluscuamp. | hubiéramos sembrado(that) we had sowed |
| Pret. anterior | hubimos sembradowe had sowed |
| Imperativo | sembremoslet's sow |
| Imper. negativo | no sembremoslet's not sow |
you (informal) — one person you are familiar with
| Presente | siembrasyou sow |
| Perfecto | has sembradoyou have sowed |
| Subj. presente | siembres(that) you sow |
| Subj. perfecto | hayas sembrado(that) you have sowed |
| Futuro | sembrarásyou will sow |
| Condicional | sembraríasyou would sow |
| Fut. perfecto | habrás sembradoyou will have sowed |
| Cond. perfecto | habrías sembradoyou would have sowed |
| Subj. futuro | sembrares(should) you sow |
| Indefinido | sembrasteyou sowed |
| Imperfecto | sembrabasyou used to sow |
| Pluscuamp. | habías sembradoyou had sowed |
| Subj. imperf. | sembraras(that) you sowed |
| Subj. -se | sembrases(that) you sowed |
| Subj. pluscuamp. | hubieras sembrado(that) you had sowed |
| Pret. anterior | hubiste sembradoyou had sowed |
| Imperativo | siembrasow! |
| Imper. negativo | no siembresdon't sow |
you all — informal plural, Spain only
| Presente | sembráisyou all sow |
| Perfecto | habéis sembradoyou all have sowed |
| Subj. presente | sembréis(that) you all sow |
| Subj. perfecto | hayáis sembrado(that) you all have sowed |
| Futuro | sembraréisyou all will sow |
| Condicional | sembraríaisyou all would sow |
| Fut. perfecto | habréis sembradoyou all will have sowed |
| Cond. perfecto | habríais sembradoyou all would have sowed |
| Subj. futuro | sembrareis(should) you all sow |
| Indefinido | sembrasteisyou all sowed |
| Imperfecto | sembrabaisyou all used to sow |
| Pluscuamp. | habíais sembradoyou all had sowed |
| Subj. imperf. | sembrarais(that) you all sowed |
| Subj. -se | sembraseis(that) you all sowed |
| Subj. pluscuamp. | hubierais sembrado(that) you all had sowed |
| Pret. anterior | hubisteis sembradoyou all had sowed |
| Imperativo | sembradsow! |
| Imper. negativo | no sembréisdon't sow |
he, she, you (formal) — one other person — formal you shares it
| Presente | siembrahe/she sows |
| Perfecto | ha sembradohe/she has sowed |
| Subj. presente | siembre(that) he/she sows |
| Subj. perfecto | haya sembrado(that) he/she has sowed |
| Futuro | sembraráhe/she will sow |
| Condicional | sembraríahe/she would sow |
| Fut. perfecto | habrá sembradohe/she will have sowed |
| Cond. perfecto | habría sembradohe/she would have sowed |
| Subj. futuro | sembrare(should) he/she sow |
| Indefinido | sembróhe/she sowed |
| Imperfecto | sembrabahe/she used to sow |
| Pluscuamp. | había sembradohe/she had sowed |
| Subj. imperf. | sembrara(that) he/she sowed |
| Subj. -se | sembrase(that) he/she sowed |
| Subj. pluscuamp. | hubiera sembrado(that) he/she had sowed |
| Pret. anterior | hubo sembradohe/she had sowed |
| Imperativo | siembresow! |
| Imper. negativo | no siembredon't sow |
they, you all — several others — plural you shares it
| Presente | siembranthey sow |
| Perfecto | han sembradothey have sowed |
| Subj. presente | siembren(that) they sow |
| Subj. perfecto | hayan sembrado(that) they have sowed |
| Futuro | sembraránthey will sow |
| Condicional | sembraríanthey would sow |
| Fut. perfecto | habrán sembradothey will have sowed |
| Cond. perfecto | habrían sembradothey would have sowed |
| Subj. futuro | sembraren(should) they sow |
| Indefinido | sembraronthey sowed |
| Imperfecto | sembrabanthey used to sow |
| Pluscuamp. | habían sembradothey had sowed |
| Subj. imperf. | sembraran(that) they sowed |
| Subj. -se | sembrasen(that) they sowed |
| Subj. pluscuamp. | hubieran sembrado(that) they had sowed |
| Pret. anterior | hubieron sembradothey had sowed |
| Imperativo | siembrensow! |
| Imper. negativo | no siembrendon't sow |

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