When keeping an eye on your neighborhood, you often need to compare what different residents are doing. In English, instead of repeating an entire action across clauses, we use phrases like "does so" or "does it" (e.g., "I check the locks, and my neighbor does so too").
In Icelandic, you avoid repeating an active verb phrase by using the construction gera það (to do so / to do it). You simply conjugate the verb gera (to do) to match the new subject, followed by the pronoun það (it).
| We support the neighborhood watch, and the neighbors do so too. | Við styðjum grannavörsluna og nágrannarnir gera það líka. |
| I investigate the burglary since no one else does so. | Ég rannsaka innbrotið þar sem enginn annar gerir það. |
Adding Adverbs
When you need to add an adverb like ekki (not), líka (too / also), sjaldan (rarely), or aldrei (never), it is placed directly after gera það.
| We report the burglary, but the guard does not do so. | Við tilkynnum innbrotið en gæslumaðurinn gerir það ekki. |
| I turn on the outdoor light at night, and she does so too. | Ég kveiki á útiljósinu á kvöldin og hún gerir það líka. |
| An unfamiliar man walks around the neighborhood, but he does so rarely. | Ókunnugur maður gengur um hverfið en hann gerir það sjaldan. |
| We lock the doors regularly, but they never do so. | Við læsum dyrunum reglulega en þeir gera það aldrei. |
Giving Reasons
This construction is incredibly useful for keeping your sentences concise when you are explaining reasons and connecting clauses with conjunctions like af því að (because) or þar sem (since).
| I use a motion sensor because the neighbor does so. | Ég nota hreyfiskynjara af því að nágranninn gerir það. |
| I read the group chat because you do so. | Ég les skilaboðahópinn af því að þú gerir það. |