One of the most confusing things you run into when learning a foreign language are homonyms and homophones.
A homonym is one of two or more words spelled and pronounced alike but with different meaning. An example of this is the word “bear”. One definition of this word is to carry, bring, transport, move, convey, take, fetch, deliver, tote, lug. Example: The man came bearing gifts for all of the children.
A homophone is one of two or more words. A “bear” is also a carnivorous mamma. A homophone is pronounced alike but different in meaning or derivation or spelling such as to, too and two. “To” is a preposition used in the infinitive case and a preposition indicating a destination. Example: I am going to the store. “Too” means in addition or also. Example: I am going to the store too. “Two” is a number. It is the sum of one plus one. Example: I need to buy two cartons of milk.
The spelling of homophones in English is a big problem even for native English speakers. The one I see that is probably the most problematic is there, their, and they’re. “There” is in or at that place. Example: Please stand over there. “Their” is a possessive pronoun showing ownership. Example: That is their car. “They’re” is a contraction of the third person pronoun – they + are. Example: They’re going to the store.