Verb conjugation of "strive" in English

It would be an advantage if you could send it via DHL, UPS or another Currier, because the parcel was lost once when we sent it with regular mail. Please send me a reference number after you send it.
We have learned that some tenses, such as Present Tense are easier and not as complex as others. Is that right? In my opinion, tenses in English are much easier than in the Spanish language.
How long have you had your dog? Does your wife take him for a walk too? Please send me my e-mails to the address listed below and add your own pictures too. I want to know a lot about you.