1.希望:wish/hope (when it is used as a verb) In Chinese it is different with others that it must be followed by a sentence,not a word or phrase. ex.1)我希望他送我一个礼物。(I hope he will give me a present) ex.2)我希望明天会更好。(I wish it is better tomorrow.)
2.需要 :need/want In Chinese it can be followed by a word or a sentence.ex.1) 我需要一本中文书。(I need a Chinese book.) ex.2) 噢,亲爱的,我很伤心,我需要你。(oh,dear,I am so sad ,I want you are my side.)
3.要+noun means want/need/ask for ex.1)我要一杯茶。(I want a cup of tea.) ex2) 他要一个助理。(He needs an assistant.) ex.3) 我要个三明治。(I ask for a sandwich.)
要+phrase or sentence means ask for/be going to do sth.
ex.1) 我要去北京。(I am going to Beijing)ex.2) 妈妈要我去商店。(Mom ask for me to shop.)
4.想要 can be followed by a word or phrase.
想要+noun means want to obtain something.
ex.1)我想要一份礼物。(I want a gift.)
想要+verb.means want to do something.note:in this statement,想要 is more like an auxiliary verb,and 要 is often dropped
ex.2)我想要去北京/我想去北京。(I want to go to Beijing)
ex.3)我想要看电视/我想看电视。(I want to watch TV)