1. The Pronoun se - Part 1
In Spanish, the word se has three uses: as the third-person singular and plural reflexive pronoun, as a pronoun in impersonal expressions, and as a pronoun in passive constructions. Se never functions as the subject of a sentence.
Functions
The reflexive se is like the English himself, herself, itself, or themselves. The verb is either the third-person singular or plural, to agree with the subject.
Muchos niños se entretienen Many children entertain themselves
viendo la televisón by watching televisión.
Note: se is also the reflexive pronoun for Ud. and Uds.
The impersonal se is used like English subjects such as one, you, people (in general), or they. It indicates that people are involved in the action of the verb, but no specific individual is identified as performing the action. The verb is always in the third-person singular.
Se ve mucho la televisión en People watch a lot of television
los Estados Unidos. in the United States.
No se encuentra mucha progra- You don’t find a lot of cultural
mación en la televisión. programming on television.

2. The Pronoun se - Part 2
The passive se is similar to the impersonal se in that the agent of the action is either unknown or unimportant to the message of the sentence. The speaker simply wishes to communicate that an action is being done to something. The verb is in the third-person singular or plural, depending on whether the thing acted upon is singular or plural.
No se refleja la realidad. Reality isn’t reflected.
No se producen programas Cultural programs aren’t
culturales. produced.
However, if a person or more than one person is acted upon and is preceded by a, then the verb remains in the singular.
Se perjudica a los niños. Children are harmed.
Se estereotipa a las mujeres. Women are stereotyped.

3. Conditional Tense Forms
To form the conitional, add the conditional endings to the infinitive, whether -ar, -er, or -ir verbs. These are the same endings as in the imperfect of -er/-ir verbs.
lanzar acceder emitir
lanzaría accedería emitiría
lanzarías accederías emitirías
lanzaríamos accederíamos emitiríamos
lanzaríais accederíais emitiríais
lanzarían accederían emitirían
Functions
To express states, actions, or events that have not yet come to pass. They may or may not eventually happen, depending on the circumstances.
Pagaría más para recibir canales en español.
I would pay more to receive Spanish-language channels.
The case described here is that you may or may not have to pay more for this service, and that Spanish-language channels may or may not become available.

4. Contrary-to Fact Statements - Part 1
To express conditions contrary to fact, use the conditional tense in the main clause and the past subjunctive in the clause introduced by si (if).
Forms
To form the conditional, add the conditional endings to the infinitive. These are the same endings as in the imperfect of -er/-ir verbs.
Conditional endings: -ía, -ías, -ía, -íamos -íais, -ían
To form the past subjunctive, add the past subjunctive endings to the verb stem based on the third-person plural form of the preterite tense. Note that, if a verb is irregular in the preterite, it is also irregular in the past subjunctive.
Past subjunctive endings: -a, -as, -amos, -ais, -an
INFINITIVE PRETERITE PAST SUBJUNCTIVE STEM
mejorar mejoraron mejorar-
incluir incluyeron incluyer-
prohibir prohibieron prohibier-
hacer hicieron hicier-
Notes:
The past subjunctive of hay (there is/are, from haber) is hubiera.
The nosotros form requires a written accent mark: mejoráramos.

5. Contrary-to-Fact Statements - Part 2
Functions
To express what needs to take place for the consequence to happen. The reason these statements are called contrary to fact can be seen in the following example.
Estela viajaría si tuviera dinero. Estela would travel if she had the money.
The fact is that Estela is not going to travel. She does not have the money to do so. If she did, she would travel (consequence).