Practice and Practise
There is often confusion over the words practice and practise. In order to understand which to use, you must know the difference between a noun and a verb. This is because practice is a noun, but practise is a verb.
If you follow US convention, you don’t need to worry about this as you can use practice for both noun and verb. If you follow UK convention and you’re not sure how to spot nouns and verbs, there are tricks you can use to help you.
Practice = Preparation
Practise = Prepare
Examples:
You need more practice. 
(“practice” – noun)
( “You need more preparation.” This sounds okay. Therefore, practice is correct.)
You should practise more.
(“practise” – verb)
( “You should prepare more.” This sounds okay. Therefore, practise is correct.)
They practice in the office for 10 weeks and are then sent out. 
( “They preparation in the office for 10 weeks…”This is nonsense. Therefore, practice is wrong. It should be practise. Using the substitution method, it would be: “They prepare in the office…”)
Keep practicing that stroke until the whistle blast. (Keep practising that stroke until……..)
If you are having difficulty of remembering the difference between “practise” and “practice” then you can try using anyone one of the three methods given below. You should be able to use one as an easy way of remembering the difference between them:
i. Practice with a C is a noun, and practise with an S is a verb.
ii. Practice is a noun. It is a thing because it has the word ice in it which is a cold, wet and slippery thing and practise is a verb – a doing word. It is not a noun becauseise is not a thing.
iii. Practice is a noun. It as the word ice in it, which is a noun. Practise is a verb. It has the word is in it, which is a verb.
So remember in the United Kingdom, as well as, in other English speaking countries “practice” is the noun and “practise” the verb; but in the U.S. the spelling “practice” is mostly used for both the noun and the verb.
Reference: Grammar Monster and Tell Me Why Facts
