Poder : To be able to
In Spanish, the present tense puts the stress on the second-last syllable. So the stress made in this case is on the letter 'O'. Generally, when stress is put on 'O', it breaks into UE. Hence in the present tense Poder becomes Puedo, Puede and Puedes.
Puedo : I can
Puede : You can (when said formally)
Puedes : You can ( when said to a friend or to a known person, i.e. informal)
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Similarly,
Tener : to have
This is an irregular verb that becomes Tengo in the first person present tense . Similar to 'O', when stress is put on 'E', ti breaks into IE, so,
Tengo : I have
Tiene : You have (when said formally)
Tienes : You have ( when said to a friend or to a known person, i.e. informal)
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Now in English, we have the subjunctive tense when we say "GO !"or "COME". It can be thought of as a command tense, when we are making a strong request or giving a command. In spanish, when we use this tense on tener, it becomes tenga : HAVE !
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e.g.
Quiero poderlo : I want to be able to do it.
Puedo correr : I can run
Puede leer : You can read
Puedes ben conmigo ? : Can you come with me ?
Quiero tenerlo : I want to have it
Tengo un libro : I have a book
Tiene una bicicleta : You have a bicycle
Tienes que benir conmigo : You have to come with me ..
Tengalo : Have it !
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