Don’t say: “I have difficulty to wake up early.”
Say: “It’s difficult for me to wake up early.”
Or: “It’s hard for me to wake up early.”
(more informal, more common)
In spoken English, the word hard is frequently used instead of “difficult.”
The phrase “I have difficulty” can be used before a noun, and the phrase “It’s difficult” or “It’s hard” is used before a verb:
- I have difficulty with grammar. / I have a hard time with grammar.
(grammar = noun) - It’s difficult for me to understand English. / It’s hard for me to understand English.
(remember = verb)