If you are learning English because you intend to travel in England and wish to be understood there, do not try to speak English perfectly because if you do, no one will understand you.
Though there is no such thing as perfectly correct English, there is presentable English which we call ‘Good English’, but in London nine hundred and ninety nine out of every thousand people not only speak bad English but speak even that very badly. You may say that even if they do not speak English well themselves they at least understand it when the speaker is a foreigner, the better he speaks the harder it is to understand him.
Therefore the first thing you have to do is to speak with a strong foreign accent, and speak broken English: that is English without any grammar. Then every English person will at once know that you are a foreigner, and try to understand and be ready to help you. He will not expect you to be polite and to use elaborate grammatical phrases. He will be interested in you because you are a foreigner.
If you say: “Will you have the goodness, sir, to direct me to the railway terminus at “Charing Cross,” pronouncing all the vowels and consonants beautifully, he will suspect you of being a beggar. But if you shout “Please! Charing Cross! Which way? ” you will have no difficulty. Half a dozen people will give you directions at once. Spoken English and Broken English.