Answer:
1. Él (when there is an accent it's the third person masculine pronoun, without an accent is an article)
2. Esta (ésta with an accent in the E is not used since 2010)
3. Tu (tú with an accent is a second person pronoun, whereas tu with no accent is a possessive adjective)
4. Mí (mí with an accent is the first person pronoun, mi with no accent is a possessive adjective)
5. Mi (same explanation as 4, in this case we are using mi since it's "mi experiencia" or my experience)
6. Té (té with an accent is a noun for tea, te with no accent is a pronoun)
7. Te (it's the same explanation as 6, but here it's used as a pronoun)
8. Solo (sólo with an accent is no longer used, but it meant only, with no accent it means alone. However, this difference isn't used anymore)
9. Más (más with an accent means either more or plus, with no accent it's a conjunction that works similarly to "pero")
10. Si (si with no accent is a conditional, translated into "if". With an accent it's an affirmation translated into "yes")
11. Sí (same explanation as 10, here it's an affirmation)
12. De (de with no accent is a preposition, whereas dé is a cojugation of the verb dar meaning "to give")
Explanation:
This examples are all of something in Spanish called "tildes diacríticas" or diacritical accent. Usually accents tells us which syllable should be stressed in pronunciation, however these are used exclusively for monosyllables, and help us differentiate one word from another when the meaning could be ambiguous. The RAE (Real Academia de la lengua Española or Royal Academy of the Spanish Language) in which cases it is correct to accentuate a word in these cases and sometimes they change the rules Such as in sentences 2 and 8, which were changed in 2010.
