"आमिर दिल्ली से है इसलिये वह अँग्रेज़ी बोलता है।"

Translation: Aamir is from Delhi so he speaks English.

[VishBhai]

इसलिये -> इस means this and लिये means for. So इसलिये means thats why.

[LittleKey]

Thank you, it helps to learn what the components mean.

[JamesLocht]

"Therefore" is a perfectly literal translation of "isliye" and should be accepted.

[no.name.42]

Do they speak a lot of English in Delhi

[ShivJain123]

Why is neccessary to write "from"?

[no.name.42]

Because of the "से." It wouldn't make a lot of sense to say "he is Delhi so he speaks English" because that makes it sound like he is the city of Delhi.

[Greta178]

Yes

[JamesLocht]

See comment above