1. Strong or emphatic personal pronouns are used to emphasise and are pronounced with greater stress. They can be used independently of a verb or other word.
2. Weak or clitic personal pronouns are monosyllabic. They will be dependent upon another word.
3. In colloquial speech nominative forms may lose their initial ε, the use of an apostrophe in the written form is optional.   e.g. ήρθα 'γώ (I came)
4. Accusative forms lose their initial ε when following από or για, no apostrophe is used. The plural forms become monosyllabic and therefore lose the accent.   e.g. για μας (for us)
5. The final ν is optional, often being used before a following vowel.
6. τις is used before a verb, τες after a verb.   e.g. Αν τις δεις, πες τες να έρθουν. (If you see them, tell them to come.)