What makes it difficult is a word that has different pronunciations based on its part of speech. For example, if I write the word record out of context, some will read it as a noun and some as a verb. If the first syllable of the word is stressed, REcord, it's a noun; if the second syllable of the verb is stressed, reCORD, it's a verb. This kind of word is called a heteronym.
In context, it becomes easier to distinguish, of course:
Here's a record of my expenses.
My students record my lectures.
However, for English learners, it is still a challenge.
