How can I write in Tamil language with Google Handwriting Input? OS - Android 4.4.2
Phone - Huawei Honor 6
UI - EmotionUI 2.3

I want to add additional language (Tamil language) under Settings - Language &amp; Input - Language, how can I add it?

If I could add Tamil, I could use that in 'Google Handwriting Input'. Or Is there any other way to install Tamil language, so that I could write in Tamil with Google Handwriting Input?

Earlier, I set up 'Swype for Huawei' as default keyboard, long pressed in space bar, selected 'More Languages' 'Download languages', downloaded and installed Tamil, but I could use this only in 'Swype for Huawei' keyboard, not in other 
keyboards.
By default, Google Handwriting Input uses current system language only. However, you can turn off this feature and select the languages you want to use manually.


Open Google Handwriting Input app
On the bottom, tap Configure languages
Turn off Use system language
Below that, select any languages you want to use (e.g. English and Tamil)
Tap Download languages to download the configured languages to use it.



(Click to enlarge screenshot)
Now you can choose Tamil (or any languages you previously selected) for Google Handwriting when inputting on a text box.


Based on Google Handwriting Input version 1.1.